well, I'm going to be called a big nerd for this....

To be a jedi, with all the powers of wolverine from X-men. that way I'd live happily as a jedi, and have immortality with the kick-ass healing ability, to develope my power for as long as needed. plus, the ability to heal anybody of any ailment. (oh, but unlike the typical jedi, I'd still listen to plenty of metal and smoke weed every day . and hey, with the healing I'd never face any health consequences).