Here are some great fonts to use for programming. I checked out the Proggy family and the Dina font (which is actually here on DC.com) and they are very nice.
Programmers have very particular font needs. A font for programming must be monospaced, extremely readable, and must sharply distinguish between similar characters, such as capital O and zero and the number 1, capital I, and lowercase L. In addition, good programming fonts allow you to view more lines of code on screen at once.
from MoeRL 
