Cinematography and the actors were just excellent.
But I voted "1" because I will never get over how D&D killed the main character John. He's fought all his life incredibly bravely for the living against the dead - but the writers gave Arya the triumph to kill the NK. Jon is the rightful heir - but not he but Bran becomes the new king. Jon frees Westeros from "tyrant Dany" and was an honest man all his life - but not he but the corrupt Bronn ends up in the council....
Thus, in my eyes, they ridiculed all the R+L=J- story. They punished the hero, who always burned for doing good to a dreadful life in a deadly desert of ice - to let the heartless and the greedy rule and thus teach us a shamelessly cynical lesson.
I will never forgive them.