I'm the opposite. Evil characters are more preferred for me because the protagonists start getting really boring after a while. Least villains tend to shake things up now and again with various gimmicks. Such as:
Batman Villains: I could list specific ones, but, let's face it, there are a lot of excellent choices for good villains. Scarecrow, 2-face, Clayface, Joker, etc.
Zombies: Call em infected. Call em zombies. Call them 4Chan users. Call em what you like, they are the scum of the earth and they are out to simply feed on the flesh and/or brain-matter of the human race. They're not evil, they are just there doing their thing and we have to fight against that.
Magneto: His villainy is questionable as he has often been shown doing good as well. On top of that, his stance isn't truly evil. All he wants is for a better world for Mutant Kind. So what if it doesn't include normal humans? But the fact that his plans incorporate murder of a large population of the human race gets him an "evil" label. Fine with me, he's still pretty cool