I would definately choose stopping time, because I could do ANYTHING that way, I wouldn't have to go to school, I could just go to the store and steal some Twinkies. Best of all, I could stay in frozen time for years, and go back exactly where I was before and trick all my friends when I show up with a moustache.
I would pick the power of "thinking" aw to freeze stuff like you or anyone but not freeze time like nick_coolhaha. My secound one would be to readmind's like noname said.