I can write as much as I'm asked to, provided other RP'ers are giving enough to go on as well. Writing is half my degree, after all. As far as genres go, I'm really open minded and interested in pretty much anything that is unique enough. The only stuff I tend to avoid is history (as I'm not well-versed) and fandom type stuff. There are exceptions, but I'm much more interested in fresh ideas with room for growth and creativity.
If I really had to pick favored stuff though, I'm really into writing slice-of-life, and I've been hankering a sort of low-fantasy, surreal/fairy tale type setting for a bit now.