Well, I'll amend your thought to say that is only used EFFECTIVELY as parody these days. There are still a number of weak stories and movies in particular that have really weak villians. Go watch any generic horror movie for example.

You have a point. There's so many stories where I can't comprehend why the villain is evil (although when done well, an evil for no reason -villain can be the creepiest one). Being powerhungry, or bitter because of something that happened in the past work best for me... And villains who think they're not being evil at all, who can reason so well to themselves that they can justify their evilness, I find those ones to work really well.

Then of course there's the ones who are just insane. :3 Like Joker, I don't know anyone who doesn't like Joker :P

Go watch any generic horror movie for example.
Oh, yeah. I forgot that kind.

I think that to be really effective a villian, like any other character, has to feel like a real person. They have to engage the reader on an emotional level, and I think those who accomplish this beyond the "man, I really hate that guy" level are most successful. I mean, look at Dracula. He is an extremely deep villian and ends up being almost sympathetic by the end of the story.

i've always kind of liked dracula... he's so very good. i find that often the most well developed character in a story will be the villain, because the writer wants ot make him/her believable.