1. When Dark Sansa enters the game.
Ooh, girl. Everything else that happened after this last season aside, this moment made it clear that Sansa Stark has come a long way since her days of serving as, for lack of better words, Joffrey Baratheon's little b***ch. We were so happy to finally welcome her to the game! (Took her long enough.) We just wish she hadn't put her trust in the slimy and traitorous Littlefinger, but what can you do. This is Game of Thrones, after all.

Side note: Arya and Sansa's mother, the late Lady Catelyn Stark, is also most deserving of an honorable mention when it comes to powerful female characters who damn well do their own dirty work.