Game of Thrones (2011)

Clear an evening for the ninth episode of season three and do not say a word about why. The show stages its biggest blow there rather than saving it for the finale a week later, so a first-timer who has learned to relax before the last episode gets caught completely off guard. On your side of the couch, the rewatch is all dread: every polite smile and every uneasy glance in that episode plays differently once you know. Be honest about the commitment, though. It is a long run, and the final season splits fans hard, so agree up front that you will finish it together and argue about it afterwards.