I'm a guy, and I think it depends on the designs. For example, I absolutely REFUSE to play as a girl in D/P/Pt or HG/SS because I don't really like the female character designs. However, I'll occasionally do it in Crystal or FR/LG, because the Crys and Leaf designs are much better than, say, Dawn. And plus, I've played the 1st and 2nd gen games a lot, so I'm getting a little tired of playing as Red and Ethan over and over again. 3rd and 5th gen games I don't really prefer any one over the other, and I haven't played through them that much (I don't know why), so I usually play as the male.