9. The Facts of Life (1979-1988)
The longest running sitcom of the 1980s was a spinoff of Diff’rent Strokes, which ran from 1978 to 1986. In fact, when the show ended its long-standing run in 1988, it earned the distinction of being the longest running NBC prime-time series to date, per Sitcoms Online.
The Facts of Life centered around Edna, a housemother at a New York female boarding school, who was the former housekeeper for the Drummonds in Diff’rent Strokes. The show documented the ups and downs of a group of adolescent girls, who were under the guidance of Edna. Throughout the shows’ seasons, Edna also experienced many joys and tribulations, including a promotion to school dietitian and eventually making the decision to leave the school altogether.