1. 'Blackwater' (Season 2, Episode 9)
The best episode of the series features the best battle ever aired on TV, hands down – but it's much more than just scaffolding for an incredible set piece. Written by the creator himself, George R.R. Martin, and directed by action specialist Neil Marshall, it gave war a human face, and its outcome real stakes. For every massive wildfire explosion, there was a quiet calm-before-the-storm conversation between warriors. For every battering-ram assault, there was a parent fearing for their child. And for every bold heroic charge, there was someone shattering under the strain. No episode was more spectacular, nor truer to the spirit of the series. If Game of Thrones were Led Zeppelin, "Blackwater" would be its "Stairway to Heaven." Long may it burn.
Rob Sheffield revisits 'Game of Thrones' most gamechanging moments – from the Battle of the Bastards to the reddest wedding of them all. Watch here.