Mad Men (2007-2015)
Matthew Weiner knew where it was all going from the start -- and the AMC show's creator even warned us in the third-season premiere, via a Don Draper line to Roger Sterling: "I keep going to a lot of places and ending up somewhere I've already been."
The series spans many eras as we travel throughout time: the 1960s change the people around Don, and the second half of the final season, set in 1970, is momentous. Betty confronts her own mortality. Peggy discovers that true independence isn't as clean-cut as she thinks. Pete breaks his life in two so that he can put it back together again.
And then there's Don Draper: well-meaning, self-destructive, creative genius Don Draper, who dreams big and falls hard over and over and over again. Mad Men asserted itself as the Great American Television Show by being hyper-specific -- designed down to the desk stapler -- and universally opaque. We’ll never stop talking about the ending, the beginning, and everything in between, so you'd better hurry up and get on our level if you're not already.