Corsair Vengeance K95
Note, it is $150 now, but when I bought it it was $130 and newegg pretty regularly has 5% or 10% discounts.
You can get them for significantly cheaper, here is one at $70:
CM Storm QuickFire TK CHERRY MX Brown
Regarding the keyboard I got specifically, it has a metal frame and thus both is study as hell and looks/feels really high-end. It has brilliant backlighting and 18! programmable keys which should be interesting.
Getting down to the mechanical aspect itself, I've never been a snob about keyboards, I've been perfectly content with the cheap keyboard that came with my boxed computer, but I kept hearing gamers rave about mechanical keyboeards, so I figured it must be worth trying.
It is amazing. It really surprises me just how enjoyable it makes typing.
If you do a lot of work with computers (I guess that would be almost everyone here) or programming, I think it is one of the better investments you can make.
Someone already posted a link to a subreddit covering the topic, and it is important that you realize that different colored switches have different characteristics and some prefer one to the other, but reds seem to be the most popular.
is a good place to keep an eye out for sales if you don't want to take the plunge immediately.