Before Mass Effect I would, 99% of the time make a male character in a game, given the choice. But I think I've just become bored of playing the same type of character over and over. FemShep was completely different. I instantly found her more interesting than maleshep and I'm now so used to Shepard being female, that I have no interest in playing with a male Shepard anymore.
I have also never created a backstory or personality for a character in a game prior to FemShep. Usually because in the games I played, the characters were either pre-defined, or just a silent, expressionless avatar that I had no attachment to. Shepard was different and I actually wanted her to have her own history and personality, especially after I started visiting this thread. It was more fun to go through the game thinking, what would Hrist do? And not what do I want to do? I doubt I would have ever done that with a male Shepard.
I'm also a straight male and the whole, 'guys who play as a female must be gay' argument doesnt make any sense to me. If I play a game with a big muscle bound bloke, I'm straight, but If I play a game with a female character that I find attractive, I'm gay? The logic in that doesn't add up I'm afraid. And I'm not saying males who play games with a male character are gay either, before someone takes that route.
And to chance subject briefly. I made a final wallpaper for my 'FemShep class Wallpaper' project. It's a sort of cover image, for the whole thing, staring all six Shepards.