So far...
Gaius Baltar from the 2004 BSG. What a lousy bastard.
Seymour from FFX, but he was really just a true irritant.
Joff Baraetheon, as everyone has said.
Theon Greyjoy, for also being a lousy little bastard.
Vyce of Tactics Ogre: LUCT. Really, man; we survive together as war orphans for years and you're ready to flip on me just like that?
The Forsaken from the Wheel of Time. Bunch of over-inflated bags of wind.
Freaking Hikawa from SMT: Nocturne. Was happy to do that bastard in.
I can't think of anything that's ever really got me infuriated, though. Joff made me physically ill at times, and Gaius makes me sigh and roll my eyes, but I can't think of a villain I was ever like "I can't wait to get you." Well, there was Saren, but I didn't feel much real antipathy; I just don't like being smack-talked. I tend to feel that level of dislike for bad protagonists than good villains. Good villains just make me happy, ironically, because it's a lot easier to invest in a story with a great villain.
Actually, just after having written that, I remembered how blindingly angry Cinderella's step-family made me when I first watched the Disney film. But I can't even really enjoy stuff when I get like that, so I just had to walk away.
Now, as for "real life" villains, Hulk Hogan's heel turn in WCW actually made me cry. He was my hero as a kid. His subsequent descent into ignominy is something that weighs heavily on my heart.