28ER

Aired: NBC, 1994-2009

The show that launched George Clooney's career had a 20-year gestation period between the time Michael Crichton first wrote the pilot in 1974 and John Wells guided it to the top of the ratings in the mid-1990s. Crichton, when ER first got on the air, said he was adamant that the show reflect his own medical training in an emergency room. "The actors were very uncomfortable talking so fast, at first," Crichton said to Written By of his edict that the show mirror the chaotic environment of triage work. "I was insistent on their being able to rattle off the tech talk, which is even more difficult." The show lasted 15 seasons, through cast departures and new arrivals, becoming the most signature medical series in television history.