I have found that I dislike fonts that have overly squared-off corners, in which all the letters look so uniform. So, I just don't understand the appeal a lot of boutique "programming" fonts like proggy or monoid.

I tend to like monospace fonts with a bit more rounded corners, which to me gives them a bit more "character" (one could almost say quirkyness) and readability.

good examples of this would be Bitstream Vera Sans Mono, Monaco and to a lesser extent, Iosevka