Nothing beats a good character arc, when heroes overcome the lies they've believed and change irreversibly. Character development is the cornerstone of any good television series, and there's particular satisfaction in the arc of a villain turned ally. Who doesn’t love watching someone become better?
Rather than villains who are introduced only to become superheroes or sporadic allies, let’s look at characters who were introduced as antagonists, only to somehow become a beloved member of their series’ inner circle. We’re talking Cordelia in Buffy the Vampire Slayer or Vegeta from Dragon Ball Z: characters we truly hated when we met them, but who arguably end up more likable than the flagship hero (especially Vegeta in Dragon Ball Super).
So, take a trip down this list and decide for yourself which inadvertent rehabilitation was the most successful. Walter White breaks bad; these characters break good. (Be warned: Spoilers abound, so tread lightly on shows you haven't watched yet.)