Vivisection, and the parts put into canisters attached to 155mm high-explosive rounds, and shot out of a M777 howitzer. Because rather than my body being burned or slowly rot underground, I think it's a far better fate to be obliterated by artillery.
Also, if it isn't possible for my body parts to be shot out of a M777, I'd like my body (in one piece) to be the target of an Excalibur round. To me, it's an awesome thing for my corpse to be vaporized by a $50,000+ (ours were $75,000) round.
Failing all that, viking funeral, because it's a HELL of a spectacle.
What? I am many things, but before all else, I am a performer, and even my funeral will have flair and style.