I have been searching for years for a decent programming font (that is, monospaced). Over the years, I've found various ones that suited me, but recently I found ranks as my favorite: Droid Sans Mono, Dotted.
Essentially, cosmix created a dotted and slashed zero variant to Droid Sans Mono, part of the Droid family of fonts designed for Google's Android operating system.
They are designed to very legible, and I have found the Sans Mono to be clean and pleasant when in the terminal or in a coding window. It also has pretty decent Unicode support.
My previous favorite coding fonts have been: Monaco, DejaVu Sans Mono, Consolas, and Lucida Sans Console.