Weezergirl:
I would say do what you always dreamed of.
Or if you can't think of anything, do cool things like parasailing, deep sea-diving, ballooning, hand-gliding. Or even if it's just visiting a place you always wanted to see.
I'm quite lucky! I've already done 5 things on my list of stuff I want to do before I die. That's pretty amazing.
I have:
-Gone to Europe
-Joined a choir and performed "Handel's Messiah"
-Gone to a Roller Coaster Park and ridden EVERY ride(I'm terrified of roller coasters yet I did it!!)
-Married the guy of my dreams...and done the nasty
-Became a mother
Other things on my list are: become a professional dancer, painter and a few extremely frightening things(to me) like parasailing, bunji-jumping, etc.
I doubt I will be able to do all of them. But somehow I'm not upset about it! I've been very blessed so if I knew I was going to die my only sorrow would be that my family would suffer for a time.
Edit: oh, I just thought of the other thing I've always wanted to do--sounds crazy but I'd love to work at an orphanage helping the children. I don't know if there are orphanages in big 1st world countries but there are several where I come from and I always wanted to work in one and be with the children. Eh, softy/motherly heart, I suppose...