Blackbolt. Controlling mind sounds cool and all but I don't want that kind of responsability. With BB's powerset I'd be a god in the most classic sense of the word, it would be great to explore the world and marvel at the miracles of the universe. And flight, flying unaided feels really cool.
Some of the arguments for becoming Xavier just give you the same mundane pleasure you'd get from busting your brain with drugs, except you can force others into going on a trip with you. So not really all that appealing to me.