This top four could easily be shifted into any order. All four moments are cruel, unjust, and staggering in their own right. Prince Oberyn was a Westerosi rockstar, a lover of wine, women and war, and his death was just as colourful. He'd seemingly triumphed in the trial by combat, but blinded by vengeance, Oberyn was caught off-guard and received a merciless death at the hands of the Mountain. His teeth were smashed out, and his skull was ripped open via his eye sockets. It's the most bloody, violent death in the show and that alone would make it a dumfounding moment, regardless of the fact that the storyline itself was hugely impacted.