I think that as far as execution goes, i would like to be taken up to an extreemly high altitude, and then pushed out of a plane.... i have a thing with flying, and this way, i would have some idea of what it is like (i could always just go sky diving, i suppose). Also, you wouldn't really FEEL the impact would you?
Failing that, i thing that i would like to be stuck in a barrel and drowned.
~Kindred