Best/Worst: The Growth Of Margaret
Margaret (Kelly MacDonald) has always been a fascinatingly complex character; this season, she became doubly interesting with the added sub-plots of her lust for Owen (Charlie Cox), Nucky's new right-hand, the revelation of her Irish family's presence in America, and her willingness to play the role of gangster's wife, like when she stole Nucky's ledger for him while the police raided his office.
But then her daughter coming down with polio ignited a fiery Catholic guilt that became a little bit too much towards the end. It seemed like an easy excuse to stir up conflict between her and Nucky. Things between the Margaret and Nucky have the potential to be very interesting next year, though, especially after the slick move she pulled in the final minutes of the season, signing over her land deed to the church.