* You have the truly evil villains who ooze pure evil. No 'why' about it. They are just EVHUL because they are. A good example would perhaps be the El Mages from CL Wilson's Tairen Soul series. Or the Sith from Star Wars. Hmmm. Maybe it's me, but the truly evil villains seem to crop up a lot in fantasy. Oh, and into this category falls the ever so frequent stalker who makes an appearance in just about every contemporary romance novel I pick up...and a few historical romance novels :) They stalk because they are obsessed and they are obsessed because....let's not detail that, let's just obsess and stalk the heroine, shall we? (Can you tell I'm not a fan of that particular plot device?) I'm becoming less of a fan of the truly evil villain. They feel....I don't know, rather one dimensional in their evilness.
* Then you have the villains with a reason (if one can call it that) behind their evilness. Greed mostly - greed for power, greed for money, etc. Greed. Revenge. Jealously. All those 'wonderful' human traits. I can understand them, but understanding does not mean condoning. The villain in His At Night (Sherry Thomas) falls into this category I think (although I'm only just over halfway through the book so he may move into the previous category as the book progresses).
* And that leads me to villains that aren't...or villains that are, but cross that line in the sand. Nope, I haven't gone mad (well, no more than usual :) Is it possible? Can a villain be redeemed? Such a cataclysmic shift depends completely on the author, whether he/she can pull it off enough that the reader can believe the redemption path. I think perhaps CL Wilson's Gaelen falls into this category. And maybe JR Ward's Zsadist? And can we forgot Darth Vader?
* And last but not least is the pretend villain. For example the (eventual) hero of a historical
So, have I missed any villain categories? What type of villain do you love to loathe?