[Shandrax]

My answer would be something between 2 and 5.

Apart from the obvious metaphysical claim, that you will live on in the memories of other people and only die once you are forgotten, there is something else, something more real. If you die and you get buried, worms will eat your corpse. Your genetic material will be transformed and parts of you end will up as parts of the worm. Birds will eat that worm and so on. Humans stand on the end of the food-chain and eventually you will be "re-born", at least partially. That is only "true" for those who believe that their soul and their body is a unit though. If you define yourself by your soul only, then you have to resort to the metaphysical theory above.

All other theories are just wishful thinking, because ultimate death would be simply way too embarrassing.