10. Jaime Lannister
This list begins with perhaps the most insulting part of this final season, the character assassination of Jaime Lannister. Over 7 seasons, we have seen the Kingslayer grow and become far more compassionate than the man who mercilessly attempted to kill Bran in the first episode. We've seen him leave behind the woman he loved and join forces with Jon against the Night King only to ignore all of that to go back to Cersei to die under a pile of rubble.
This is all the more insulting given that this bizarre decision came directly after sleeping with Brienne. It reduced what could have been an earned romance solidifying Jamie's face turn to a shameless piece of fan service completely ruined by everything that happened after.
Perhaps the worst thing about it all is that this move comes after he learns Bronn has been hired by Cersei to kill him and Tyrion. The things we do for love...