I used and loved TotalFinder, but it was sooo buggy (specially when copying large files off external drives) that I ended up uninstalling it in disgust. I'm using vanilla Finder.app right now, and don't miss it terribly.
If you need a 'Finder Pro', I suggest PathFinder. version 6 looks promising. I might be tempted to buy it: http://cocoatech.com/pathfinder/
* Moom (http://manytricks.com/moom/) - allows you to move windows around a lot easier.
* TotalFinder (http://totalfinder.binaryage.com/) - Finder with tabs and other useful bits.
* CoRD (http://cord.sourceforge.net/) - Decent RDP client (better than the official Microsoft one).
* Caffeine (http://itunes.apple.com/gb/app/caffeine/id411246225) - Stops the screensaver activating at the click of a button.
* CleanMyMac (http://macpaw.com/cleanmymac) - Can strip the unwanted language packs etc from applications saving you a significant amount of space.
* Enqueue (http://www.enqueueapp.com/) - Decent iTunes replacement, with FLAC support.
* Flu.x (http://stereopsis.com/flux/) - Warmer screen during dark hours, makes it easier to work in dim light.
* SourceTree (http://www.sourcetreeapp.com/) - Decent GUI Git/Hg/SVN client.
* GrabBox (http://grabbox.devsoft.no/) - Instantly throws screenshots into your Dropbox public folder.
* iStat Menus (http://bjango.com/mac/istatmenus/) - Memory and CPU utilisation in your menu bar.
* YoruFukurou (http://itunes.apple.com/gb/app/yorufukurou/id428834068) - Decent Twitter client with muting rules etc.