19. "The Lion and the Rose" (Season 4, Episode 2)
Normally, a wedding would be ruined if the groom got murdered at the reception. But there was nothing normal about this matrimonial man of the hour — the sadistic boy-king Joffrey Baratheon. Played by brilliant young actor Jack Gleeson, who retired from showbiz immediately after shooting this episode, Joffrey was a top contender for the most entertainingly loathsome TV villain of the decade. His protracted on-screen poisoning made his "Purple Wedding" — named after the color his slap-worthy face turned as he asphyxiated — nothing less than the social event of the season.