Milotic-I hate nearly everything about this wierdo. It seemed like a knock-off to you-know-who. And I only disliked it for that. But then in my first Nuz of diamond, the champion's bastard of one killed my first catch and I now ofishally(yeah that's a pun :3) LOATHE Milotics.
Rattata-There is nothing I like about this ****er. I hate it's design, I hate it's stats, I hate how commin it is, and I hate it more than ANY other mon in the world. It never should've existed.
Klinklang-See the fist point. I like inanimate object mins, but this one took it too far. But my dislike transformed into a burning despise once it killed one of my best teammates in Black 2, and that caused me a LOT of trouble in victory road.
There are more, but here are the ones I feel should be removed from the game at all costs.