Top 5 villains who haunt my nightmares

Writing books tell me I'm supposed to like the three-dimensional antagonist who is just a reflection of myself, who is justified, blah, blah, blah.  And I do enjoy the depth of those like Zach's father in Personal Effects:  Dark Art.

But my very favorite villains are psychos all the way!  I love quirky bad guys with a method to their madness that makes sense to them if not to anyone else.  I want them to be passionately motivated \with varying levels of emotion.  I like a villain with sense of humor, that bit of humanity wrapped in evil chills me.

Sylar - from Heroes.  omg this guy puts a face to the bogeyman under my bed.  All he wants to do is figure out how things work….an innocent enough pursuit for a nice enough guy.  Until he graduates from dissecting watches to dissecting brains.  Aside from ripping abilities out of people's minds, he has no interest in hurting anyone.  It's just an unfortunate side effect of the process.  Unless they get in his way, which of course they do, and then he has no choice.  I like this idea of a villain 'forced' into his villainous actions.

Dread - from Otherland by Tad Williams.  This guy constantly has a song in his head, usually classical music.  There's something very disturbing about a man who kills not out of anger, but with serenity.  He's specific about his violence, not one of those bad guys who tries to make it into the Guinness Book of Law-Breaking.  He has zero interest in being a sexual deviant, finds it disgusting.

The Joker - primarily the incarnation from The Dark Knight.  He's dedicated to the challenge of anarchy.  He's gleeful about destruction and his stories about his past contradict each other so you don't really know why he is the way he is…maybe there's a hint of truth in all of them, or maybe he had a perfectly well-adjusted childhood and is just rationalising why he is how he is.  One of the most interesting moments with him is when he says that he would never want to kill Batman, despite how much he seems to try.  Batman is his companion in freakdom and the challenge that keeps him stimulated.

The Dark Man - from Personal Effects:  Dark Art.  I've never been terrified by an elusive 'dark presense' before but wow.  I love the hints of madness and how the protag fails to maintain his sanity in the face of the abnormal.  

Zcythe - from Lightning Spliced.  Okay, okay, she's my own villain but I had to get a female up here.  This girl loves killing people because she thinks it's fashionable from her custom knives to the skull clips in her pigtails. She's so happy-go-lucky I can't help but want to hang out with her.

One thing these villains all have in common is that they are far stronger than the protags that fight them.  Just when the protag thinks they've got the antag cornered (Joker's in jail), all hell breaks loose.  The antags push the protags to the edge–off it–buildings explode, people die, drama ensues!