Ignoring having superpowers or being a vampire, and just sticking to more realistic dreams...
1. (Actually possible) - Win the lottery. Not some crazy amount, even $10M clear would be enough. I would make sure a few special people don't have to worry about money again. I would use the rest to travel and party for about 2 years, then ctb.
2. (Not possible) - have my body become 21 years old again. This would be great because I already finished school and have a good job. I would work hard and play hard for a while, then CTB when I would be around 30 physically.