I'd like to donate. I'm an organ donor. Failing that, I think I'd be happy as a med-school cadaver. One of the few reasons I've wanted to go to med school is for the dissections. I'd like to give someone that experience. If my shell's not in good enough shape for either of those, cremation is the way to go. Scatter my ashes over some of my favorite places. The shore of Lake Michigan, the Grand Canyon, the rocky shallows of the James River.
'Course, I'd be dead. Can't say I'd care that much.