5. 'Battle of the Bastards' (Season 6, Episode 9)
To paraphrase an old joke, what do you call a thousand dead slavers at the bottom of the ocean? A good start. That's certainly the approach of this pivotal episode in Game of Thrones' sixth season, which begins with Daenerys raining fire and blood upon the Masters of Slavers bay – and it only gets more sweeping and disturbing from there. Its true showcase is the titular conflict between Jon Snow and Ramsay Bolton at the walls of Winterfell, a cataclysmic conflict that leaves literal mountains of corpses strewn across the battlefield. The horrors of war have rarely been more horrific.