"Jon Snow avenged the red wedding. He is The White Wolf, the king in the North!"
Holy cr@p, words cannot express. Any who, for me, I'd say the entire battle of the Bastards. The deaths of Roose Bolton, Ramsay Bolton, and Walder Frey. Basically anything with Jon Snow (Especially the confirmation that he is Lyanna's son, likely Rhaegar's, unknown if he's trueborn or still a bastard. Plus, succeeding Robb as King in the North) were the highlights for me.