One thing I like about Inconsolata Pro is that it supports Cyrillic fonts (the other two also support), there are many good monospaced fonts which don't have Cyrillic support, and there are lot of programmers who like to make the comments in the code in their native language.
Though, there are two best "programming" fonts according to me: - free: Droid Sans Mono ( http://en.wikipedia.org/wiki/Droid_(font) ) - paid: Pragmata ( http://www.fsd.it/fonts/pragma.htm )
One thing I like about Inconsolata Pro is that it supports Cyrillic fonts (the other two also support), there are many good monospaced fonts which don't have Cyrillic support, and there are lot of programmers who like to make the comments in the code in their native language.