7. Tywin Lannister
Daddy Lannister had what is probably the least dignified death of all Game of Thrones deaths: sat on the lavatory.
He deserved it though; Tywin, father of Cersei, Jaime and black sheep of the family Tyrion, had a history of being, well, a bit of a twat. And so when Tyrion shot him with a bow and arrow in the middle of having a poo (presumably), he well and truly deserved it.