69, also known by its French name soixante-neuf (sixty-nine), is a sexual activity. In this position, two people orient themselves such that each person's mouth is near the other's genitals, simultaneously performing oral sex. This position can be performed in opposite-sex or same-sex pairings.
Consolas in spanish is as close as it gets to the "masturbate" verb inflection (specially for women, where there's even the "consolador" device - a.k.a. dildo). Although according to some that would pretty much describe the sensation of using it, I doubt that was the idea behind the name
Similar letters like O, 0 and o and l, I, 1 have to be easily distinguishable.
Good, distinctive punctuation eg square/round/curly brackets, commas, full stops etc.
Attractive, because I like good typography
And it has to maintain these characterstics in normal, bold and italic variants. So far, Consolas is my favourite but prior to that I tried things like Courier New, Monospace etc but they're not as nice. I find Courier's serifs make things look a bit fussy, Monospace managed to look good at one font size and looked fairly ugly at others etc.
Some programmers seem to value getting the maximum lines of code on screen, but I'm not that fussed myself.
And then you get things like the so called 'ultimate programmers font', Profont, which is about as fugly and unreadable as these things get, so yeah - whatever works for you really.