Abobo. He is da man after all.

lol

I didn't expect you to post anything else!

Kefka!!!!!!!

Yep. I concur! Kefka is a fucking legend!

Ghaleon (pwns sephiroth)

Ganon

The Joker in the Arkham games. The voice acting my Mark Hamill was amazing and the script was very well done. I genuinely looked forward to the cutscenes.

GLaDOS

Well, the opposite of my answer yesterday would be Dark Samus.

Magus from Chrono Trigger, probably because you can eventually recruit him. 

Kefka. The ultimate villain. He's intelligent yet maniacaland twisted, he's ruthless yet calculated. He destroys the fucking world before the heroes even get to try and defeat him. He has the best final boss music from any of the Final Fantasy games. Done deal.

Cell.

Ganon (Twilight Princess version) and The Emperor (Dissidia: Final Fantasy version).

I agree with the chaps that said Kefka. So evil!

Volgin...Man, He's so bad you just have to love hm!

The Illusive Man (Mass Effect)

Kreia.  The most complex villain in any video game ever. 

Gotta jump on the Kefka band wagon. He was sinister, greedy, crazy, and ruthless as hell. He's like the Joker of the Final Fantasy universe.

this guy!!

He's like a demented version of walt disney!

What? STOP looking at me like that!

Wesker from RE series. SOB just won't die! Now he has Matrix moves in RE5? WTF?

Goldman from House of the Dead. It's not because he's a good villian but because he's so bad at being bad its good.

Blinky, PInky, Inky, and Clyde.  Runners up include Kefka, GlaDOS, etc.

Kefka plus infinity.

I will say Liquid Snake. Had a lot of style for a villain....gotta give him credit.

G man from Half life, I love how we know so little about this dude..... and never will until Valve pull out their finger and make the third one!