Aliens. I do wish they would expand them some, especially power wise.. but then again I might not like the restrictions put on them by taking them in a particular direction. I have a common theme I like to play out where aliens come down to explore or and eventually dominate the sim world. (Get outta here, McFly!)
I play vamps now and then, more often as victims though. My use for them has picked up some though but maybe it's the supernatural type. Weird because I love classic vamp stories. I just can't seem to get into creating them myself. I have high high hopes for Witches though.