I used to play male characters only, often "good guys", then one time I was tired of them, and decided to make a female elfe character in neverwinter nights that could be sum up as a damned ***** that kills anyone that is non useful for her. I'm not identifying particularly to this kind of character, but it was a kind of real role play, I was playing a role when playing with her, and I really enjoyed it as is.
Then I didn't played much any other female character for a while (didn't play any RPG either), but some years later, I played wow: when I created my first character, I knew that I will spend tons of hours looking at my character, so I had to really enjoy it.
After about half an hour looking at the different races, classes and sex, I created an elf female druid and enjoyed it for some months, before going to another server that was opening and create there a human blond paladin female. Most of my male reroll haven't get close to the 60/70 cap, so I can say that I prefer to play some good looking female rather than a terminator / musclor looking male (casters don't have to look as strong).
I played about a year in Vanguard and played a high elve female bloodmage as my main character, but I was disapointed because female are not especially good looking in this game (not talking about ****s, just that they have about no feminity, including in their animations, they are looking like robots...)
On RFOnline and L2 some female characters were especially good looking (from sex bomb to cute girls) and it was hard not to play them
On Lotro I currently play 2 male and a female. Female aren't looking very good and their animation either, but the possibility offered by the game to play an old man is really great and I find the dwarves especially awesome and good looking.
I think that on Aion, about 3/4 of my character will be females because they look really great