I'd live for as long as the world doesn't end or get completely screwed, lol. I'd hate to be stuck here while the world falls apart, and I'd hate to live forever if I have to watch my family and friends die and be forced to hide out among society, like those Tuck Everlasting people. But other than that, a nice long while would be pretty cool. Especially if I didn't have to age and deal with painful illnesses that come with old age.