Consolas
Along with Windows Vista, Microsoft shipped a collection of new fonts optimized to work with sub-pixel rendered anti-aliasing (specifically, Microsoft’s ClearType technology).
One of those fonts, Consolas, is mono-spaced and intended for command lines, text editors, and everywhere crotchety old geeks demand that their letters and numbers line up into vertical columns.
It is a very nice looking font, and has (for the moment at least) replaced Bitstream Vera Sans Mono as my text editor font of choice. Consolas has a proper italic face, while Bitstream Vera Sans Mono only has an oblique. I have TextMate set up to italicize variable names and comments and the greater visual difference between the roman and italic faces makes it much easier to see the semantic structure of a block of code at a glance. The design of the characters is closer to that of the [MPW Font](http://en.wikipedia.org/wiki/Monaco_(typeface)) than Vera Sans Mono; I used the MPW Font day-in and day-out for a number of years and am still fond of it, so Consolas get extra points for nostalgia. Oh, and did I mention that Consolas is designed for sub-pixel rendering? Because that really does make a difference.
The only problem I had with Consolas, and the rest of the ‘Vista font’ family, is that you had to buy Vista to get them without resorting to underhanded means. Fortunately, that is no longer a problem.
