As long as I have a chair that works (even one that slowly descends), a desk that's not too badly beaten-up, a decent monitor (I agree with Knut on the resolution) and the basic SSMS I can do whatever I need to do.

I also use Office packages for dumping data in, image manipulation, etc.

My only real "nice-to-have" is a second monitor (or even a third if I can get it).