39. Walder Frey
Plenty of Game of Thrones villains are great players, and are recognized as such. But gods damn it, Walder Frey was the architect of the Red Wedding, the most shocking event in the series! Inviting people to celebrate your daughter's nuptials and then murdering them at the reception made Lord Walder one of Westeros's worst men … at least until Arya forced him to eat his own kids before slitting his throat. No more wedding plans for him.