All my characters are guys. Hmm. Somebody write a novel with an awesome girl character already!
Anyway, I'll have to say Obi-wan from Star Wars. I mean, telekinesis, a laser sword, a place on the Jedi Council, a nice retirement home on Tatooine...I'll take it. Plus, Ewan McGregor's pretty hot.
I also get compared to Severus Snape from Harry Potter more than any fictional character. (Because I'm a moody, sarcastic chemist?) Not the most flattering comparison for a twenty-year-old girl, I know, but because there's a slight chance he'll end up doing something marvelously heroic and saving the day, I'll go with him. He's got the greatest sense of humor, after all. And, again, Alan Rickman was at one point pretty hot...
And finally, for the sake of having some pure sci-fi, I'd be Daniel Jackson from Stargate. The old Daniel, before they butchered his character come season 8-9. *grumbles* He doesn't have to do much fighting, but he has all this cool knowledge. And he gets to be ascended!