I play a mix of characters, mostly because I am a role player at heart. I choose gender baced off what I think is cooler for the character. Case in point; my Shepperd in Me and Me2 is female... because I think a badass female Shepperd is, well... badass. However, my male rouge/ranger in dnd is a male because the image of the character in my head was that of a male. I't all depends on what I want for a character at the time of creation, and so I have no preference (with the exception of LotrO, where male hobbits just can not be taken seriously. I mean, at least female hobbits don't look hilarious 100% of the time.)