Oh my... I have lot of characters. *glances through work-in-progress* Yes, I have a lot of characters, though only a few main ones. In Daughter, I have around twenty-five named characters, at least, and there's a pretty even split between male and female characters. In Tom I currently have five, three men and two women.
As far as a preference, I'm not sure I have one. I think the majority of my main characters tend to be female, especially in my sci-fi/fantasy work, and if I had to pin some reason to that, I'd say it mostly has to do with my own personal life. Most of my close friends have been women, and I've always been closer and identified more closely with my mom and grandma than with my dad and grandfathers. The majority of my bosses have been women, and often the majority of my co-workers in general.
Sorry, got a little tangental there. In any event, as I said, I tend to write more women than men for mainline characters, so I suppose I prefer to write women, though I hadn't thought about it until now.