Ooh! Joe and I were talking about this one the other day.
I have no issue with cremation, but because I love trees and I'm a sap (no pun intended), I'd like to be buried on my own property (which is possible, apparently, with Council permission) and have a tree planted directly over my grave. That way, my physical essence will directly benefit another living thing.
Joe wants to be shot into space, preferably in a funny pose so he freezes that way.