5. Eddard Stark
He was the biggest character, played by the biggest actor, at the center of the biggest storyline and all the promo posters and trailers and commercials…and none of that could save him. Ned's dead, baby, and while his surprise execution is what made Game of Thrones part of the pop-culture pantheon, it's his hangdog sense of duty and honor — he died because he respected the value of the lives of freaking Cersei and Joffrey! — that made us care about him, and the show, in the first place.