Here's my shortlist of fave fonts for editing source code. Some of these are built in to MS Windows, others were supplied with Corel Draw 8 (my favorite illustration tool.)

I prefer monospaced, but some times I switch to a proportional font for variety - modern editors do a pretty decent job of dealing with them.

Monospaced:

• Lucida Console (Old Reliable)
• Courier New (boring, but it works)
• Monospace 821 BT (wide spacing, great for those late nights)
• QuickType Mono (very similar to Lucida Console)

Proportional:

• Comic Sans MS(!)
• Verdana (clean and omnipresent)
• Bell Gothic BT
• Century Gothic (clean, crisp)
• Futura Light BT (clean, crisp)
• Gill Sans MT (heavier, taller, still clean)
• Microsoft Sans Serif (larger and boring but works well enough)
• Murray Hill Bold BT (whimsical)
• Technical (whimsical, fun - I wish I could write like that.)
• Tw Cen Mt (fat)
• Vrinda (clean but lots of vertical spacing, and I don't know where the heck it came from)

What's your favorite source editing font? I'm always looking for new fonts.

Know of a place to download TrueType (or other scalable) fonts that are well suited to source editing? (Clean monospaced fonts seem to be hardest to come by.) Shoot me a URL and I'll post it.