1. Irresponsible Children - Those stupid little kids that can't take responsibility for their own damn shit, and write their names all over the games or controllers.
2. Careless People - People that just throw their games (Especially CD games!!!) around, then when you buy it at SwapUSA or GameStop, it dosent work (This applies to carts that you can't test. I hardly ever buy a CD game at one of those places, because none are scratch-free!).
3. Fucking Retards - These include: Excessive fanboys (I don't mind a little fanboyism now and then. Hell, look at my posts about music and you'll see that I'm a Led Zeppelin and Iron Maiden fanboy.), Lying people (This super-special copy of Combat is indeed much rarer than Xenophobe!.), and actual fucking idiots.
Bonus/Runner Up: Old people/irresponsible parents - People who blame violence on video games. "Lil' Billy went out and sliced through his teacher with a kitana we bought him for Christmas. He played True Crime so much, he thought It would be OK to kill a person. So in turn we are suing Nintendo, Micro($$$)soft and Sony for letting children buy these games. They have no place in the world." Well, Lil' Billy is a fucking idiot, and so are you!