The Trial of Tyrion Lannister (Episode Six: 'The Laws of Gods and Men')
Offered the chance to dodge the executioner's sword if only he'd cop to a crime he didn't commit and live out his life on the Wall, Tyrion is triggered into self-destructive rage by the coerced testimony of his estranged prostitute ex, Shae. The resulting soliloquy vented decades of resentment and hatred for his family and the society they dominate like an inactive volcano suddenly smothering a city in ash. For Tyrion Lannister, it was the speech of a lifetime. For Peter Dinklage, it was an Emmy reel.