Ramsay Bolton (Game of Thrones)
Want an easy indication that Ramsay Bolton is one of the most effective villains? Just look at how universally appalled people were after he raped his new wife Sansa in Season 5. (And in front of Reek/Theon, no less.) Of course, most people blamed the Game of Thrones writers and showrunners, rather than the fictional Ramsay, but barely anyone took a stance that Ramsay wasn’t actually evil enough to do the devious deed.