We spend a lot of time looking at our screens. So you'd think I'd have looked at fonts earlier, but I never really found anything I liked. After mucking around this weekend, I've come to like Andale Mono for my life with vim and an xterm.
Granted, Andale Mono has been part of the corefonts package, so I presume that my preferences have just changed. Maybe they'll change in the future, and since I'm a complete font newbie, that's probably the case. But for now, Andale Mono is it.