Cremation, bury the ashes under a nice tree, or on a nice mountain after a hike.
Why cremation? well, for one thing, I don't like the idea of decomposing slowly. For two, no one can dress my dead body in a suit (it's SO not my style. It would be so messed up for any friends). And three...if there is ever a "zombies rise from their graves" thing, I will not be contributing to the problem.
As for the funeral...One formal one for any old family members who want/DEMAND it, and then a huge gamer party for everyone else, because, well...why the hell not?