OS X user here. While I generally prefer Menlo¹ myself, I’ve found myself predominantly using Everson Mono² simply because of the wide range of characters it supports in Unicode’s BMP (and unbelievably, SMP as well!). I’m pretty sure it contains glyphs for more Unicode codepoints than any other monospaced font mentioned here. Not to mention that it was created by Michael Everson³, who has made a sizeable number of contributions to the Unicode Standard himself.

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¹ — https://en.wikipedia.org/wiki/Menlo_(typeface)

² — https://en.wikipedia.org/wiki/Everson_Mono

³ — https://en.wikipedia.org/wiki/Michael_Everson