Season: 2
Air Date: 12/11/11

Boardwalk often gets unnecessary complaints regarding its measured, deliberately-paced storytelling. Sure, it can move slow, but it rewards your patience beautifully with fantastic conclusions, like the the one-two narrative punch of powerhouse penultimate season two episode "Under God's Power She Flourishes" and the finale "To the Lost." 

The finale is barely a year old, but it entered the pantheon of classic TV moments instantly, thanks to one of the boldest creative decisions of all time. The best writers place story first, and while many fans were outraged and saddened by the loss of a major, beloved character, none could argue that the decisions each character makes isn't true to the person we've spent two seasons learning about, and the story itself.