10. Ramsay Bolton
Like an experiment in creating a character with no redeeming qualities whatsoever, the psychopathic son of backstabbing Lord Roose Bolton was sick enough to make Joffrey Baratheon look like Eddard Stark. But actor Iwan Rheon's gleeful, almost giddy style turned him into the closest thing Westeros had to a bona fide supervillain. Eventually, his victim Sansa Stark gave him a taste of his own medicine by giving his dogs a taste of him. His crimes were hard to watch, but the character himself never was.