Fira Sans: a Free, Open Source Typeface Commissioned by Mozilla
I wandered the internet for years looking for the perfect monospace font for me.  There was never anything that fit; Ubuntu Mono was nice but a bit too "unprofessional", Liberation/Droid too boring, Microsoft/Apple fonts didn't fit either.  I looked through so many font comparison sites, tried a whole bunch, just ended up sticking with the defaults.Then I found Fira Mono.  I use it everywhere.  It looks great; it's very clear and easy to read, it has a nice style.  Fonts are a very personal thing so thanks to Mozilla for finally letting me have one that was "mine".