I’ve been watching through ER and it’s reminding me of how much turnover there was of the main cast. By the penultimate season, there was not a single main character remaining from the first season. As far as I can tell, the only characters that appeared regularly throughout every season were the nurses (who are secondary characters).
Are there any other scripted TV shows that experienced an entire main cast change? Not necessarily all at once, and excepting pilots.
The only others I can think of besides ER are soap operas and Law & Order.
…
That said, on a side note I must say that ER was remarkably consistent with actors and characters. There are actors who only appeared in one or two scenes in a given season but that actor would continually reappear throughout the entire 15-year run. Often there are multiple seasons between appearances, and reappearances sometimes don’t even come with lines, they’re just walking around in the background.
CSI rotated out most of its cast. George Eads was the only cast member who stayed with the series throughout its run. And then he didn’t appear in the finale.
Greg Morris was the only cast member who was a regular on Mission: Impossible for the entire series.
Most of the cat on MASH was turned over during the series. Alan Alda was the only cast member who appeared in every episode.
Temperatures Rising had two complete turnovers of the cast. Only Cleavon Little was in all three seasons.
The Joey Bishop Show went through several incarnations of supporting cast; Joey Bishop (obviously) was the only one who remained, and his character, though keeping the same name, changed from a press agent in LA to a talk show host in NYC.
Toma was a cop show that had modest success. But after the first season, lead actor Tony Musante didn’t want to continue, so they cast Robert Blake in the role. Blake insisted he didn’t want to be a replacement, so the character was changed a bit and renamed Baretta.
The British series Misfits replaced the entire cast over the course of series 3 and 4.
Extending to animated shows, The Transformers completely redid the cast after the movie (aside from bringing Optimus Prime back at the end of season 3) - Galvatron was arguably the same person as Megatron, the same doesn’t apply to the rest of the cast.
The second season of Operation Petticoat (not to be confused with Petticoat Junction) replaced all but three of the main characters from the first season.
Speaking of Petticoat Junction, I think only two actors - Linda Kaye Henning and Edgar Buchanan - were in every season.
I think Mariska Hargitay is the only person left from season 1 of L&O: SVU, but Ice-T has been there since season 2.
Ellen turned over almost the whole supporting cast from season 1. The only one kept was Arye Gross, who seemed like the weakest character to me; but, if they’d kept Maggie Wheeler, she wouldn’t have been available to appear as Janice on Friends, and she deserved some kind of special Emmy for that recurring character. It’s gotta be tough to appear in just a few episodes per season of a long-running show, and keep the character so consistent.
William Christopher was also on the show for every season. But George Morgan played Father Mulcahy in the pilot episode. After that, Christopher was a recurring guest star like Jamie Farr. He became an official cast member in the fifth season.
Wasn’t Greg there the entire time? His role ON the show changed, but I think he was present throughout all the seasons
But, IIRC, only the first two seasons are called “Power Rangers” the rest all have some kind of subtitle associated with them, which makes them an entirely different show.
Skins also replaced the entire cast. And they did it twice. (The show is about students at a sixth-form college in Bristol and follows them for the two years they are at the school. In six seasons, they showed three generations of students going through college.)
And Shameless replaced almost the entire cast. When it started, it focused on Frank Gallagher and his children but over the years, all of the children left and, while Frank was there throughout, he wasn’t always the focus, and didn’t even appear in some episodes.
The difference is, even as far back as the first season they’d do episodes where Lupus wouldn’t actually show up; but he was still a castmember, and so his name would still appear in the credits. But when The Powers That Be were effectively out to replace him with Sam Elliott, Lupus wouldn’t even show up in the credits of such episodes.