What type of keyboard do you use and why?

One thing we all have in common, is we're on the computer a lot, and we probably use the keyboard as much as or more than most other computer professionals. What is your style of keyboard that you use and why?

I started with a "plain" Dell one long ago, moved into an ergonomic style Fellowes one, and then after I broke my wrist, I needed something smaller and easier to press so I got a small gaming-style mechanical keyboard and really loved that thing. Unfortunately, it was only $25 and didn't last long. I just picked up a Unicomp Ultra Classic which is a rebranded IBM Model M keyboard and it is a bit big and bulky, and I'm still trying to get used to the buckling springs vs. the Cherry MX Blue ripoffs I had before.

Still can't tell if I like this thing, but I'm happy that it is at least working as I have research work due tomorrow. Tell us your keyboard story.