Does Superman's Super Strength include his invulnerability, too? If not, I'll take Wolverine's regeneration, which in turn, gives him a degree of super strength, because he can push himself further than any normal being due to the fact that his muscles heal nearly instantly, plus nothing in the real world would really be able to kill me with that kind of regeneration.
If I was allowed to go with the following, I'd go with these two ideas ripped straight out of some manga I like.
The first super power would be the ability to use alchemy and apply it to anything, much like Edward 'Fullmetal' Elric from Fullmetal Alchemist. It would be really handy for fixing broken things, defending yourself, building a new house... the list goes on. It would make life a lot easier and so much more fun. A life without powers in comparison is fairly dull.
The second would be the ability to use chakra like in Naruto, all the fights you could have would be awesome. It would involve training your mind to think quickly and to adapt and form new tactics over a couple of seconds. You could have tournaments like those seen in the new Tron film, where people battle it out. Obviously, you wouldn't have the killing involved, just an accepted set of rules for when a victory has occurred.
I'd include the ability to become a Shinigami like Ichigo in Bleach, but that really involves several abilities, no matter what kind of Shinigami you are.
I'd love to have time control. Then I could have all the time I need to finish various projects, and I would be able to undo several accidents such as accidentally dropping and breaking my ocarina (that was possibly the saddest thing I've done so far).
Teleporting Powers. Bathroom too far away, just use teleportation. Being chased by a killer, use teleportation. Playing tag and you're really slow, just use teleportation when someone is chasing you. Need to get to Ganon's tower really fast, use teleportation.