http://www.pckeyboard.com/
Here's one that's very popular with the guys at work, and we're all a bunch of really nerdy infosys geeks, so you know that if we say it's good, it's good. :P Myself, I prefer to find the old school Dell 101 keyboards or NMB brand keyboards, if you can find them. NMB only sells to OEM's, so you have to know someone who is a system builder if you want one. But let me tell you, they're an awesome keyboard, and so darned rugged and heavy you could beat someone to death. lol. But yeah those are the ones I typically use. But some might disagree with that. Myself, I like to have a keyboard which requires a little bit of work to press the keys. But that's a personal preference.