20. Theon Captures Winterfell
Season 2, Episode 6: "The Old Gods and the New"
The sad, squalid, rain-soaked "triumph" of turncoat Theon Greyjoy over the forces loyal to the Starks, the family that raised him, was one of the series' best acted, best shot, and best scored sequences up until that point. The prince of the Iron Islands had been charged by his foster brother Robb with winning over his father Balon to the Northern cause. Instead, he turned on his lifelong friend to win his dad's approval, then attempted to impress the old man even further by seizing Winterfell directly. And just to show he meant business, Theon took it upon himself to behead Ser Rodrik Cassel, the aging knight who'd taught him how to wield a sword in the first place. The botched execution took place in full view of the sobbing, screaming Bran and Rickon to boot. "Victory" never tasted so sour.