If I were lucky enough to have a special power it would be something like Alice. As I am now, completely human, I have dreams and see things about the future...not in a clear cut way but I always feel when something is coming. Sometimes it's good, sometimes not so much. It's hard to trust your instincts but I think it'd be pretty awesome to have it heightened by being a vampire.
If I didn't have that power I'd probably be close to something like Jasper in the way he knows what other's a feeling and can try to help. But all that being said, I'd probably be a dud vampire hahaha.