The Joker from Arkham Asylum was a great villain, but that had a hell of alot to work with because of the decades of rivalry they had in the comics. How come Bowser or Dr Robotnik\Eggman didn't get a mention?. For me the most memorable Villain has got to be GLaDOS from portal...... She promised us cake, and then there was no cake...... you can't get much more evil than that.