In RPGs with more than one player character, my party is usually composed of 50% males and 50% females, but if there's only one character, I tend to choose a female one. And I admit for me it's mostly about the looks. If a game has pre-set looks/portraits for specific classes, genders or characters, more often than not, I even select them by looks rather than by their stats and capabilities. I check out all possible looks/portraits and go with the ones I like most, male or female. I set great stock in visuals and I want my characters to look cool to me, whether that means attractive, interesting, sympathetic, funny or even creepy in a fun way.
And most of the male choices just don't do that for me. To me they often look more or less the same, uniform, average joes or bullnecked burly men, with little variety in physique and features, and hardly any handsome, unusual, geeky or actual badass looks. And if I can't play the male characters I'd find interesting, noone I can identify with, look up to or laugh about, I prefer to play females (because I guess I'm shallow enough to always find something interesting and to my liking in them ;) ).
What I don't like is pre-set makeup and specifically "feminine" (read skimpy) clothing for my female characters though. Not that I wouldn't appreciate the option to choose make-up and skimpy clothing whenever I feel like it, but making it a default you can't opt out of is annoying. That's as if choosing a male character would always result in your character getting a mustache, because, "well, what do you want, that's manly, isn't it? All men need to have a mustache to be considered attractive!" :P
foxworks: There's nothing more fun than playing a bad-ass who happens to be a woman. Tomb Raider, Saint's Row, Mass Effect .... ;-)
Yeah, that too. :D
