My pick would be the ability to move time. Not just to go back and forward in time, but to be able to place anyone or anything at anyplace in anytime. Like if someone shot at me, I would be able to move the bullets to another time and place, say 50 years in the future to where he is and unexpecting to be hit by bullets he shot over 50 years ago! Or to like suspend myself in mid air by sending myself to that same spot at a faster rate than gravity. Or to like disentagrate things by replacing the item in the present with it's broken down future version. Or maybe step outside of the space time continuem all together and never age. Damn. Temporal manipulation abilities would be sweet!