Probably the best insight you can get on a platoon's experience in what is (or rather, was) probably the most contested area in Afghanistan.
 - http://www.imdb.com/title/tt1559549/
 - http://en.wikipedia.org/wiki/Restrepo_%28film%29
The film won the Grand Prix de la Semaine de la Critique at Cannes. It created a huge debate in Denmark about the engagement in Afghanistan.
The shooting: http://www.youtube.com/watch?v=9PcvDrYd8-4&t=15m45s
The dead taliban scene: http://www.youtube.com/watch?v=jfke2X6joko&t=3m10s
Trailer (switch to HD!): http://www.youtube.com/watch?v=0DDuRraJbOg
It's also got some amazing handheld footage of firefights. After the third or fourth time the cameraman dives for cover and the people around him begin shooting, you start to think, "hey, this seems like it was pretty dangerous to make." That only makes it sadder that the guy holding the camera was recently killed in Libya while doing more or less the same thing.
March of the Penguins (2005)
Code Rush (2000)
Losers and Winners (2006)
Documentary about the dismantling of a German coking plant, the most modern in the world, by Chinese workers in 2003, who shipped the plant to China and built several clones of it there. The plant was sold to China for a minor sum when the steel price was at an all time low and politicians believed the price would stay there. The steel price has since skyrocketed.
Excellent documentary about the rise and fall of IT-startup Biodata and its founder Tan Siekmann during the dotcom boom and bust, alas only available in German.
In addition, I like the following documentaries:
- "Client 9: The Rise and Fall of Eliot Spitzer" http://www.imdb.com/title/tt1638362/
- "Planet Earth" IMHO one of BBC's best productions with some of the most amazing nature shots ever (e.g., a [presumably stratospheric] shot that looks like fog or fire but is really a swarm of flies) http://www.imdb.com/title/tt0795176/
- BBC has also two of the best documentary series regarding the second world war: "The World at War" (http://www.imdb.com/title/tt0071075/) and "The Nazis: A Warning from History" (http://www.imdb.com/title/tt0207907/)
- Errol Morris' "The Thin Blue Line" (http://www.imdb.com/title/tt0096257/) and "The Fog of War" (http://www.imdb.com/title/tt0317910/)
I was 11 or 12 when this series first aired in the UK. It was on quite late at night, but my parents decided I should "stay up" and watch it. Good parents. The war was still raw with them, though they were tiny kids at that time. My mum was born in 1937, my dad was as bit older.
It is graphic, honest, and a since folk rewrite history as time passes, an essential historical document of what transpired in those times.
I urge you to watch it. Our recent history is the most relevant.
But let me put this in perspective. The American Civil War started 100 years before I was born. WWII started 72 years ago. What seems almost unreachable history, becomes almost tangible as you get older. And I'm not that old!
I've found the interview with Mike Pinkerton (nowadays at Google working on Chrome for the Mac) to be particularly interesting because of his candidness: http://mozillamemory.org/detailview.php?id=7277
On a similar note, The Vice Guide to Travel:
Adam Curtis is the creator of various interesting pieces. Some of his documentaries are mentioned in this thread:
I've also enjoyed many of Werner Herzog's films.
The Yes Men are quite entertaining.
Man on Wire.
Herzog has several short docus worth seeing too. I know the one is on youtube where he goes to an evacuated town and up a volcano that's set to blow, to find a man who has refused to leave his home on the volcano's side.
Do I have the wrong impression?
It's a pity, because I've learned things from watching Curtis. The Bernays-Freud material at the start of Century of the Self is riveting.
One of his latest ones, "It Felt Like a Kiss" is a new direction for him and pretty interesting from what I saw of it. It's almost mocking his own style in some ways -- it uses the techniques of typical TV news media to show a series of absurd and shocking material, with the context switching rapidly enough that there's no chance to reflect on what you've just seen. I suppose it's a meta-criticism of the TV news medium, mimicking it in an extreme way to show how ridiculous and harmful it is. It's an exciting trip to watch, though the content is nonsense and it doesn't have a whole lot to say -- it's more just a way to get you to reconsider the usual media you might consume.
Adam Curtis does have political opinions about society. If opinionated films bother you, and particularly ones that lean left or are not decidedly right leaning, it may be worth skipping Adam Curtis' work.
Ken Burns' documentary on Frank Lloyd Wright makes you feel like you identify with a singular drive for vision above all else (The SC Johnson headquarters in Racine, WI are heavenly but the roof leaks buckets)
Not truly a documentary but "My Architect" is a moving journey by Louis Kahn's son to try to understand his father he never really knew through the works he left behind
He has also released an ebook where he offers rave reviews of 150 great true films.
Each film gets a short review of why it is worth your time, and then features 4 or 5 screen grabs from the film to show you what the texture and style of the film is. It also includes a picture of the cover and indicate where you can rent it (say on Netflix) or purchase it (from Amazon).
What is he looking for in a great true film? "It must be factual. It must surprise me, but not preach to me. If it introduces me to a world or subculture that I never thought about before, even better. There's a plot - a transformation from beginning to the end."
Besides being an incredible individual, I found Robert McNamara's lessons to be surprisingly relevant to the startup world.
Errol Morris said that the way he gets such amazingly candid confessions out of people is that he asks a question, the interviewee answers it, then Errol Morris just sits there. The interviewee feels the need to fill the silence and that's where the gold comes out.
Cosmos. Because it's Carl Sagan.
If you're at a university, you could probably order it through interlibrary loan. There are actually a lot of libraries with this item and it'll likely be loaned (we do international loans all the time).
Lessons of Darkness: the aftermath of the first Gulf War in Kuwait.
Little Dieter Wants to Fly: A young German emigrates to the USA, become a Navy pilot, and is shot down in Vietnam. He escapes and lives to tell the tale. Herzog later re-made this as Rescue Dawn, but the original version is better.
Encounters at the End of the World: Herzog travels to Antarctica.
My Best Fiend: Herzog recounts his movie-making with Klaus Kinski. (For the counterpoint, read Kinski's autobiography, "Kinski Uncut.)
The White Diamond: an experimental zeppelin flies over Guyana.
Grizzly Man: Bear aficionado gets too close and is eaten. Herzog assembled this one from the aficonado's footage and narrates.
Out of all of these, I'd rate "Dieter" as the best.
Herzog's masterpiece is Aguirre:
It is head and shoulders above anything else he's ever made.
Fitzcarraldo and Nosferatu are also good:
The rest of his films range from awful to meh.
Also, The Pixar Story is terrific. Plus, both documentaries are on Netflix Instant.
Personally I use Movielens.org to keep track of movies - and based on your ratings it'll predict which other movies, including documentaries, you might enjoy.
Some of the documentaries I enjoyed are:
- Armadillo (2010). Armadillo centers on a group of soldiers, as do Restrepo, and in particular a mission where Taliban soldiers allegedly are liquidated. The documentary does a good job depicting the chaos of war situations with helmet-mounted cameras.
- Sharkwater (2006). To me, much more moving and worrying than The Cove.
- Surfwise (2007). A surf movie that isn't about surfing, but instead tells the story of being brought up in an alternative lifestyle.
It's a reminder of how crazy things were during the .com boom. Also, on how not to start a company.
Tetris: From Russia with Love - This is the fascinating story behind the game set against the backdrop of Cold War tensions between East and West.
Triumph of the Nerds: The Rise of Accidental Empires
N is a Number: A Portrait of Paul Erdös
The Ascent of Man: Written and presented by Jacob Bronowski.
Cosmos: Carl Sagan
Man on Wire is a must http://en.wikipedia.org/wiki/Man_on_Wire
It's a bit tendentious but overall insightful and interesting IMO.
(Available for streaming on Netflix.)
"BBS: The Documentary" and "Get Lamp" by Jason Scott are a couple great hacker docs, about BBSs and Interactive Fiction Games (though I would have to say they have a more Apple/wintel PC bent over other computers, but still historically interesting). Both have many great interviews with BBS and interactive fiction luminaries.
Tilt - The Battle to Save Pinball, this one covers the trials and tribualtions of Pinball 2000 the development of a digital/analog pinball hybrid. There's also The History of Pinball, its not as fancy but it's interesting.
The King of Kong is slightly entertaining about the world of Donkey Kong high scores and a peek into competitive arcade game competitions.
Revolution OS - About Linux/GNU kinda dry but interesting interviews.
Deathbed Vigil...and other tales of digital angst. Documents the last days of Commodore when it went bankrupt in 1994. I think mainly interesting to Commodore fans or folks who enjoyed seeing commodore fail...
It's a film about art, entrepreneurialism, and delusion. Also friends and family.
He will surprise you every time with the kind of stuff he asks and that people will give him actual answers, really great stuff.
Alone in the Wilderness - A guy that is built like Popeye goes into the Yukon and builds a log cabin by hand. I think its really inspirational.
Murder on a Sunday Morning: http://www.youtube.com/watch?v=8z2jtha8Oqg
God Grew Tired of Us -- About Sudanese refugees who come to live in America. They'd literally never seen any modern conveniences ever. For example they had to be taught how to use a toilet. Very fascinating. http://www.godgrewtiredofus.com/about.html
Errol Morris' movies are all good. Fast, Cheap and Out of Control is pretty widely known. But also check out The Thin Blue Line, which is built around multiple reconstructions of a crime scene and got a death penalty sentence reversed: http://www.imdb.com/title/tt0096257/
The film is composed of four interviews that seem to have nothing in common at all. Yet somehow it is compiled in a way that it makes very much sense in a way I cannot really describe. I have to watch it again, it will be interesting to see how it makes me feel nowadays.
I hear high praises for Carl Sagan's Cosmos
Michael Mosley is very good at telling you about medicine 
David Attenborough is just him really, world's most famous natural history presenter? Watch again every time you upgrade your TV  
A group of young men are accused of murder because, basically, they look like goths and have the misfortune of living in a conservative Christian community.
The "Seven Up" series:
A group of British kids from various socio-economic backgrounds are interviewed starting when they are 7 years old, and interviewed again every 7 years.
Based on Noam Chomsky's book about the influence the mass media and other institutions have on Americans.
The life of Robert Crumb, a hugely influential underground cartoonist.
About kids who are born in to insanely wealthy families.
Manufactured Landscapes: http://en.wikipedia.org/wiki/Manufactured_Landscapes
Up The Yangtze: http://en.wikipedia.org/wiki/Up_the_Yangtze
History of electronic warfare -- very surprising, recently declassified stuff.
Plus the history of Silicon Valley itself, from a pro-valley perspective.
Fat Head (2009) http://www.imdb.com/title/tt1333994/ Especially if you've seen "Super Size Me", but even if you haven't, an amusing yet educational take on the obesity "epidemic".
Food, Inc. (2008) http://www.imdb.com/title/tt1286537/ - Exposing the absurdity of our industrial food economy.
Music and Entertainment:
Anvil! The Story of Anvil (2008) http://www.imdb.com/title/tt1157605/ Talk about never giving up on your dreams.
Metallica: Some Kind of Monster (2004) http://www.imdb.com/title/tt0387412/ The other side of fame.
"When We Left Earth" - a history of NASA from Mercury through to the mid 200Xs, including many interviews with engineers and astronauts, narrated by Gary Sinise http://en.wikipedia.org/wiki/When_We_Left_Earth
Did you know that Intel's business plan was a single page double spaced and full of typos?
That Steve Jobs offered his then boss Nolan Bushnell half of Apple Computer for $50K? Bushnell passed and joked in the movie that he refused to calculate the return on that investment because it would be too painful ;<).
Last Train Home http://www.imdb.com/title/tt1512201/
Up The Yangtze http://www.imdb.com/title/tt1114277/
Discovery Channel - The People's Republic of Capitalism - 4 parts series
China Rises, 4 parts CBC series
BBC Megacities, BBC 3 parts series
Fog of War: http://www.imdb.com/title/tt0317910/
It's almost 3 hours long but it will grab your attention and you'll forget about time. When I watched it at the movie theatre in the mid-90s I was blown away by it's depth. I have never watched a better documentary since.
It's free online: http://www.hulu.com/watch/249576/hoop-dreams
Driver 23: http://fenrisfilms.com/films.html Awkward, almost painful to watch, but hard to look away.
Bigger, Stronger, Faster: http://www.imdb.com/title/tt1151309/ Unfortunately, this is the only one of these three available on Netflix Instant.
OK. So It's not quite a documentary... but a wonderful introduction to Campbell and his ideas taken from interviews with Bill Moyers at the end of his life.
Part 1: http://gosu.com/2011/06/boxers-wings-part-1/
God Grew Tired of Us - about three of the "Lost Boys of Sudan", a group of some 25,000 young men who have fled the wars in Sudan since the 1980s, and their experiences as they move to the United States. http://en.wikipedia.org/wiki/God_Grew_Tired_of_Us
Darwin's Nightmare - about the environmental and social effects of the fishing industry around Lake Victoria in Tanzania. http://en.wikipedia.org/wiki/Darwins_Nightmare
Deliver Us From Evil - tells the true story of Catholic priest Oliver O'Grady, who admitted to having molested and raped approximately 25 children in Northern California between the late 1970s and early 1990s http://en.wikipedia.org/wiki/Deliver_Us_from_Evil_(2006_film...
Shadow Company - an introduction to the mercenary and private military company industry, concentrating on the role the industry has been playing in recent conflicts http://en.wikipedia.org/wiki/Shadow_Company
Iraq for Sale: The War Profiteers - about the ongoing Iraq War and the behavior of companies with no-bid contracts working in Iraq. http://en.wikipedia.org/wiki/Iraq_for_Sale:_The_War_Profitee...
'Meet the Stans' - a four-part BBC Four series on the stans (Kazakhstan, Kyrgyzstan etc) http://en.wikipedia.org/wiki/Meet_the_Stans
'Places That Don't Exist' - a five-part BBC Four series on breakaway states and unrecognised nations http://en.wikipedia.org/wiki/Places_That_Dont_Exist
War Photographer - As well as telling the story of an iconic man in the field of war photography, the film addresses the broader scope of ideas common to all those involved in war journalism, as well as the issues that they cover. http://en.wikipedia.org/wiki/War_Photographer
Pretty much all seasons/episodes of Vanguard http://en.wikipedia.org/wiki/Vanguard_(TV_series) of which ' The Oxycontin Express' is the most famous for winning a Peabody award.
Pretty much all episodes of Vice Guide to Travel - http://en.wikipedia.org/wiki/Vice_Guide_to_Travel
Many documantaries are available on youtube. Do note though that some of these documentaries discuss horrible topics, aren't fun to watch and will be stuck in your mind for a very long time, if not ever.
Food Inc.: http://www.foodincmovie.com/
Absolut Warhola: https://secure.wikimedia.org/wikipedia/en/wiki/Absolut_Warho...
http://www.thelinguists.com/ | http://www.imdb.com/title/tt1172995/
David and Greg are "The Linguists," who document languages on the verge of extinction. In the rugged landscapes of Siberia, India, and Bolivia, their resolve is tested by institutionalized racism and violent economic unrest.
1. Century of Self
2. BBC Horizon Infinity and Beyond
3. BBC Horizon Is Seeing Believing
4. BBC Dangerous Knowledge
5. The Shadow Factory
6. Get Lamp
7. Human Experience
Hope that helps.
Restrepo is popular now too, with good reason.
Spellbound: story about kids entering a spelling bee - great film about the fabric of America
Fog of War: Former Sec of Defence talking about war
Capitalism- a love story: humorous look at our economic system
Planet Earth: Breathtaking view of our environment
did it tank in the theatres or something?
* Bigger Stronger Faster - http://www.youtube.com/watch?v=ZkL1T-CZPfs
Having said that about pot documentaries, I have to add Super High Me to the list, because I enjoyed that film as well.
Also, I'm not sure if they qualify as documentaries in the strict sense of the word, but you can't go wrong with BBC natural history programmes.
It's about the fact that most products now have a "programmed lifespan".
And the recent 'Senna' for both capturing the passions involved.
- Dear Zachery: one of my all time favorite documentaries. Amazingly tragic, depressing, and infuriating, but extremely well made. (http://movies.netflix.com/WiMovie/Dear_Zachary_A_Letter_to_a...)
- The Great Happiness Space: an interesting look into the lives of japanese male 'escorts'; the unfolding of the moral dilemmas they face in doing their job is quite fascinating. (http://movies.netflix.com/WiMovie/The_Great_Happiness_Space/...)
- Heavy Metal In Baghdad: If you think running a startup is hard, multiply that difficulty a couple times just to get an idea of what these guys had to go through just to be able to play the music they enjoy. Don't have to be a metalhead to enjoy this one, but it helps \m/ (http://www.vbs.tv/watch/acrassicauda--2/heavy-metal-in-baghd...), Also, be sure to checkout their follow-up, 'Heavy Metal in Istanbul' (http://www.vbs.tv/watch/acrassicauda--2/dvd-extra-heavy-meta...)
- Metal A Headbanger's Journey: Another one of my favorites, definitely a must watch if you're at all into metal; it basically traces the roots of metal, and explores all the different sub-genres and cultures it has spawned (http://topdocumentaryfilms.com/metal-headbangers-journey/)
- Standing In The Shadows Of Motown: Great doc about the greatest band no one has heard of; "This unheralded group of musicians had played on more number ones hits than the Beach Boys, the Rolling Stones, Elvis and the Beatles combined - which makes them the greatest hit machine in the history of popular music. They called themselves the Funk Brothers." (http://www.google.com/url?sa=t&source=web&cd=7&v...)
- This Film Is Not Yet Rated: about the craziness that happens behind the film rating process (http://www.google.com/url?sa=t&source=web&cd=3&v...)
- E=mc2 - Einstein and the World's Most Famous Equation: A look into the history behind all the scientific descoveries that led to Einstein's famous equation (http://video.google.com/videoplay?docid=4144497206440839046#)
- Maxed out: Great look into the american credit card situation (http://movies.netflix.com/WiMovie/Maxed-Out/70058892?trkid=4...)
- Who the #$&% Is Jackson Pollock?: A really cool, unique ride through the business of art (http://movies.netflix.com/WiMovie/Who-the-Is-Jackson-Pollock...)
- Mr. Death - The Rise and Fall of Fred A Leuchter Jr.: About the fascinating life of an expert executioner (http://video.google.com/videoplay?docid=654178281151939378#)
- American Drug War: a look into what the war against drugs has done to the U.S. (http://topdocumentaryfilms.com/american-drug-war/)
- Between The Folds: A surprisingly interesting oragami documentary (http://movies.netflix.com/WiMovie/Between-the-Folds/70120179...)
I'm sure I know of plenty more great ones, but these are all that came to mind at the moment...