9. 'The Door' (Season 6, Episode 5)
"Hold the door! Hold the door! Hold the door!" The jaw-dropping, heartbreaking revelation of how Hodor became the duosyllabic gentle giant we knew and love – Bran Stark’s time-travelling consciousness burned this command into his brain as a kid – dominated this horror flick of an episode, directed by Lost veteran Jack Bender. But the episode's numerous emotional reunions – between Sansa and Littlefinger in the North, between Daenerys and Jorah in the East – were each devastating in their own right.