I would say, "Geez, God. Some all-powerful deity you turned out to be. Can't you use your omnipotent magnificence to give me, oh, I don't know, EVERY GAME EVER!?!"
And God would reply, "Fuck you, buddy! This is a hypothetical situation! You only get one game, and that's final!"
And then I say, "Fine, God!", and pick Minecraft.