I came across an interesting blog post discussing different programming fonts. My current one, Andale Mono, comes in at #9. I'm impressed enough by any of them to want to switch from Andale Mono, but then I saw Inconsolata at #1.
Dang. That font is pretty sweet.
I found these instructions useful for installing it. I used the ttf which I have just added to my customize git repo.
Edit: I am sticking with Andale Mono inside Emacs but really like Inconsolata as my fixed width browser font.