Old news from Joel on Software that I finally got around to playing with:
It's a fixed width font that looks good at small font sizes, slashes zeros, etc.:
Back in the days when I did Mac development (System 6) the biggest monitors available for the Mac were maybe 9", and the only way to see a reasonable amount of code on screen was to use a tiny font. Now that I have two 18" LCD panels, the only way to see a reasonable amount of code on screen is to use a tiny font. The world is awash in lovely TrueType fonts but none of them are monospaced, which is a nuisance for programming because things which should line up won't.
Fortunately, I have found ProFont, and all is well again. For best results use the FON version, not the TTF version.
More info here: http://www.tobias-jung.de/seekingprofont/seeking.html
Well, I've been using it as my default font in notepad and Visual Studio for a week and I'm still happy with it. The TTF version seems to work best for me.