3. Paige’s Discovery

(“The Colonel,” season 1 finale)

Despite everything else, the Jennings’ marriage is always at the heart of The Americans. The relationship starts off as merely part of their cover, but over time the ups and downs of having a family bring them closer, with the stress of their spy missions simultaneously driving them apart. In the Season 1 finale, they finally get to a place where it seems like they could have a real marriage — just in time for Paige to become suspicious of what her parents are up to all the time. She then begins snooping, setting a plot in motion that continues to be a huge part of the show four years later.