It's my default monospaced font as well. I've tried Inconsolata, Terminus, Anonymous (Pro), etc. and though I could happily use most of them I find monofur to be easy on my eyes, clear, and just a little Art Deco in feel if not in history. Using it was a whim that's stuck with me for several years and I'm happy I stumbled across it. It's spread to a few friends via the "what the heck is that", "eh, might as well try it", "this is really nice!" cycle.
It's my favourite programming font because it's extremely readable but retails a little flare.