You rot and are food for worms, or
You go to Heaven or Hell (or Purgatory for any Roman Catholics out there), or
You are reincarnated into another form, based upon your karma in this life, or
You become a ghost and are hunted on poorly produced TV shows or
You become a god, if you're a righteous Mormon. Otherwise, it's punishment for you, or
You awaken in your parents' basement to find that it was all a simulation, then you decide to either play again or have a snack, or
You pass into eternal life, if you're a Rastafarian and are righteous. If not, then you just die, or
You die and everything just blinks out of existence, because you are a true Solipsist, or
Any one of a thousand other things.
As for myself, I don't know for sure. (Just between you and me, I don't think anybody else knows either.)