I would choose to relive some of the amazing adventures that take place in games and movies, like Loom, Shaun of the Dead, Indiana Jones, Morrowind, Beneath a Steel Sky, etc. I would basically do everything in my power (which would be ultimate power, of course) to turn my life into an adventure with all the right components; humble beginnings, some catastrophe, a quest to make things right, lots of danger and thrill, all of which I would be prepared for. Also of course, the end would be calm and settling, rather than an abrupt and unsightly end like me dying.
And I would make it so that both of my parents and I all die at the same time so none of us have to live without either of the other two. I would probably also extend my parents' lifetimes to accommodate for my full life.
There are probably lots of other things I'll think of later.