Advertisement'It's Always Sunny in Philadelphia' is TV's longest-running live-action sitcomDecember 02, 2021Joe HernandezfacebookEmailActors Rob McElhenney, Glenn Howerton, Kaitlin Olson, Danny DeVito and Charlie Day act during a dance scene on the set of "It's Always Sunny In Philadelphia" in 2007 in Los Angeles, Calif. (Getty Images)
