Well, since preserving ones health isn't an issue, I'd probably have unprotected sex, do a lot of LSD, maybe pick up a coke and heroin habit to see what its like, bungee jump, hang glide, base jump, use a lot of salt, eat fast food and great big rare steaks, try crack and raw chicken...

To summarize, I'd do all the things that we're usually too afraid to do. I don't believe in hell, and I wouldn't be around here anymore, so I'd have a few months of zero consequences. Nothing to lose, out with a bang.