8. Zombies (Call of Duty)
The definition of insanity: doing the same thing over and over, but expecting different results. When you play zombies in Call of Duty, you are effectively insane: you start the mini game fighting these monsters, and it's easy. One knife, one kill. But as you progress through the levels, the zombies get harder. Much harder. Not only that, but they also start to increase in number, until eventually the fun element is gone and you are in a mad dash for your virtual life, employing whatever strategies you can to make sure that they don't hit you. The most terrifying thing, though, is when you are running away from these lurching foes. You may turn back every once in a while to fire some shots, but you're running and all of a sudden one pops in front of you, or even worse a group of them. And then you're trapped. And then you're dead. No matter what you do in this game, the result is the same: you will end up dead and these terrifying monsters is the sole reason behind it. Next up, King of Terror himself...