A while ago I wrote about my experience with the Kinesis Freestyle keyboard. I’m still using it day in, day out and I wouldn’t trade it for anything else. If you’re not looking for an ergonomic keyboard though there are a bunch of options.
The Das Keyboard is one of the more popular options, but it does have that huge number pad (which is also a fault of the Microsoft Ergo keyboards.
Shawn Blanc just took up the torch again with his look at 3 more mechanical keyboards. None of them are ergonomic, which is a non-starter for me, but if that doesn’t matter then read the post and see where he ends up on the matter of the all important keyboard. If you’re a writer or programmer you type a lot and getting the right keyboard is very important.