Depends on the limits. Can I choose the ability to give myself any superpower? How about telekinesis so strong I can move entire planets, yet so precise I can take something apart at the subatomic level? Or the ability to mind control every living thing on Earth at once?
If we are talking just regular, standard superhero clichéd abilities, I'd probably go for teleportation. Being all powerful would be cool, but if there are going to be limits anyway, then I'd just as soon not bother. Teleportation is always useful for dealing with my chronic laziness. Just *bamf* and I'm in the kitchen, grab a snack, *bamf* back on the couch. Plus if I was ever in a car accident or about to get mugged, I could just save myself by teleporting away.
"I will not succumb to temptation, unless she's cute."