10 Exact Moments Video Game Villains Became Obsessed With You
9. Coming Back From The Dead - Portal 2
In the first Portal, GLaDOS didn't really hold a grudge against Chell. Her "obsession" was mainly rooted in there being literally no one else left for her to experiment on. This isn't a disqualifying factor, but it was a bit too impersonal for her to feature on a list of gaming's most obsessive villains.
And then came Portal 2.
GLaDOS awakens from her death very much steamed with Chell. As revenge for what Chell did to her, GLaDOS decides that nothing could be worse than just picking up where they left off.
GLaDOS' hatred for Chell is the stuff of memes. Petty, manipulative, and single-minded in that way only a machine can be. Even after she's forced to join forces with Chell at the midpoint of Portal 2, there's a constant underlying strain to their relationship, peppered with little asides that remind you that GLaDOS still sees Chell as more of a force of nature than an actual person.
However, what costs her points is that she gets over her obsession and just lets Chell go.