I've been rather fond of Adobe's Source Code Pro[1][2]. Notably, it comes in weights all the way down to ExtraLight. My typical setup these days uses ExtraLight in iTerm2 on retina displays. Depending on the display (and sometimes the font renderer), I'll play with combinations of weight and size to find the best fit for a given installation.

[1] http://adobe-fonts.github.io/source-code-pro/

[2] https://github.com/adobe-fonts/source-code-pro