2. Chris Brown
The hatred surrounding Chris Brown is much more black and white. The brutal end of his first relationship with Rihanna provided more than enough fodder to keep the hate going, and that's understandable. No man should ever lay hands on a woman like that. What's worse, I think, is that he's never seemed really repentant or apologetic, and instead gets argumentative, sulky, and sometimes downright insulting when anyone references his violent antics. The fact that these two got back together for a while adds to the hatred, but more than anything, I think it's Chris Brown's continued bad behavior and lack of sincerity that keep the dislike so strong.