Season 2, Episode 9: "Blackwater"
The first of Game of Thrones' four major battle sequences to date, "Blackwater" remains, in many ways, the one to top. Shot by director Neil Marshall, who'd return to helm "The Watchers on the Wall" two seasons later, the fight between Stannis Baratheon and the Lannisters for control of King's Landing and the Iron Throne took up an entire episode, from build-up to the declaration of victory by Lord Tywin. In between was the most expansive and explosive action ever filmed for television – literally explosive, thanks to the huge green wildfire detonation that blew Baratheon's navy to shrieking, smoking smithereens. With a focus on the human cost of the conflict on both sides, the sequence set the gold standard for blockbuster storytelling with heart and soul intact.