7. GlaDOS (Portal 2)
Like the original game, Portal 2 took place in the Aperture Science facility run by the evil Artificial Intelligence (AI) known as GlaDOS. The game’s protagonist Chell turned GlaDOS into a pile of burning metal in the previous game, after discovering that the cake it promised for clearing the game’s levels was a “lie”. But then GlaDOS was something of a ruthless machine, having murdered the scientists who ran the Aperture Science facility and would resort to any kind of manipulation in order to use Chell as a test subject and make her navigate the facility’s dangerous test chambers. And GlaDOS had a remarkable personality for a character who is after all a robot, and is definitely one of the most memorable villains in video gaming.