Villains!

So what qualities make a good villain? These people (or things) can drive the plot of a story, so they do need to be well done, but what makes them good?

First, some types-

Pure evil- They do evil because that's what they enjoy doing. Harm and cruelty are their passion. Often found in fantasy.
Jealous- Found in many genres, there are many villains who are not physical, but harm people in other ways, and are driven by jealousy. Common in romance.
Monster- They want to eat you. A primal fear, but not something you can understand, much.
Sympathetic villain- They have a GOOD reason for doing BAD things, which makes them dangerous. They may morph as the story goes on to become more evil, or may have a moment of clarity, and turn back.
Crazy- Crazy people may do evil things, but are THEY evil? A quandary.
Greed- The driver of many villains. Bling does terrible things to us.
Uncaring- A creature, or thing, that just kills and doesn't care at all about who is hurt. Monsters may be this, but an asteroid, comet, or world destroying engine would more easily take this in. Look up cosmic horror. This type of villain simply doesn't care.

What are some other types of villains? What's your favorite type of villain?