Besides the typical answers (money, eternal life, more wishes, 12-inch cock), I think I'd want the power to step onto a basketball court and make a shot from ANY spot on the court, 100% of the time.
Could you imagine how much fun that would be? You'd be short and slow, but you'd be the best player in the NBA. You'd be drilling shots from 35 feet. You'd be unstoppable. You could try a hook-shot from 57 feet, it would still go in.
You couldn't make EVERY shot though. You wouldn't want to go 57 for 57, cause then it would be *too* obvious that you have some sort of super-power, and then the NBA might ban you from the league. So you'd probably limit yourself to 21 for 24, 18 for 21, etc.
You couldn't constantly jack-up 71 footers either. Once again, don't want to make it too obvious. But if you need to make a buzzer-beater, then you definitely use your powers.
"The Funk Monkey, from 32 feet. GOOD! The man is on fire, that's his 17th 3-pointer of the game!"