I suppose the more correct statement is 'Protagonists v. Antagonists' but I like villains. The 'I'm here to, if not end, then seriously mess up, the world and here's my creepy laugh to prove it' sort. Maybe it's my religious upbringing but I like the dichotomy of Good and Evil, Right and Wrong. But that's not the point. This is the point: I like villains more than heroes because I think they're more interesting and take more skill to write.
Even in good writing, all an author needs for a hero is as character with a vague notion to 'do what's right'. Anti-heroes and whatnot aside, at the very basic level that is all that is required. If well written, this will not compromise the integrity of the story. Because you can just have a ridiculously idealistic protagonist.
Villains need a reason....