WARNING! This article contains SPOILERS from the season finale!
You don't want to cross Arya Stark (portrayed by Maisie Williams). That girl knows how to hold a grudge. When somebody has seriously wronged her, her family, or her friends, she puts them on her mental kill list, which she likes to recite to herself before going to sleep.
Sadly (or for the good?), a couple of the people on that list have perished at the the hands of other characters, though I'm sure Arya doesn't mind all that much. Joffrey Baratheon was poisoned at his own wedding by Littlefinger and Lady Olenna. Tywin Lannister was killed on the can by his crossbow-wielding son, Tyrion.
Arya herself has knocked three names off her list. The first was Polliver, a Lannister man-at-arms that stole Needle from Arya and killed her defenseless friend Lommy. Next was Ser Meryn Trant, the knight of the Kingsguard who presumably killed her swordfighting instructor, Syrio Forel. Lastly, in the Season 6 finale, Arya sliced the throat of Walder Frey, the man responsible for the death of her brother, Robb , and her mother, Catelyn, at The Red Wedding.
So, who will be next to die? "Arya still has a medium-length list of people she wants dead," Williams told Entertainment Weekly (in the video above). "But if I had to put them in order of who she wants dead the most, just three of them, it would probably go: Cersei, Melisandre, then The Mountain or Ilyn Payne."