Show: The Andy Griffith Show
Departed: Deputy Barney Fife (Don Knotts)
Replaced by: Deputy Warren Ferguson (Jack Burns)
Talented and hilarious Knotts is replaced by Jay Lenoish sounding, no-talent Burns–instantly forgettable. “The Andy Griffith Show”, shot in color at this point, would limp on for 3 more painful years, a shadow of what it once was.
Show: Chico and the Man
Departed: Chico Rodriguez (Freddie Prinze)
Replaced by: Raul Rodriguez (Gabriel Melgar)
Lesson learned: when your star offs himself, pull up the stakes.
Show: All in the Family
Departed: Mike & Gloria Stivic (Rob Reiner & Sally Struthers)
Replaced by: Stephanie Mills (Danielle Brisebois)
The arrival of Edith’s niece Stephanie marks the transformation of “AITF” from a socially relevant groundbreaking sitcom into another show with a smartass kid.
BEST:
Show: Barney Miller
Departed: Detective Chano Amenguale (Gregory Sierra)
Replaced by: Detective Arthur Dietrich (Steve Landesberg)
Landesberg’s dry, intellectual Dietrich provided an unusual but highly successful replacement for motormouth Amenguale.
Show: Cheers
Departed: Diane Chambers (Shelley Long)
Replaced by: Rebecca Howe (Kirstie Alley)
Proving that the writing’s the thing, Alley’s clumsy and pathetic Rebecca Howe fit in seamlessly when the show lost uptight intellectual Diane Chambers.
With too much time on my hands, I invite your suggestions.
Make Room for Daddy
Jean Hagen’s sharp and funny Margaret was replaced by Marjorie Lord’s Kathy. Unfortunately, Marjorie Lord on her best day couldn’t compete with Jean Hagen on her worst.
BEST
MASH
Larry Linville’s Frank Burns gave way to David Ogden Stiers’ Charles Emerson Winchester. I know a lot of people on this board really hate the way MASH changed over the years, ut Winchester was a far better foil for Hawkeye than the buffoonish Bruns ever was.
Um…Danson predates Harrelson on Cheers by a whole lot, and they both stayed 'till the end…
Woody replaced Coach after Nicholas Colasanto died in '85.
Actually that brings to mind a series of replacements that fits into both.
Worst:
Night Court:
Selma -> Florence, after Selma Diamond’s death. Florence was a second-rate knock off of Selma.
Best:
Florence -> Roz, after Florence Halop’s death. Instead of trying to fill the vacancy with another carbon copy of Selma and Florence, they filled it with Roz (Marsha Warfield). While holding a similar niche (Abrasive female bailiff), she was a better rounded character than Florence (or even Selma, although that was as much due to the fact that she got 6 years to Selma’s 1 as anything else).
And, as a little added bonus:
Funniest:
Also Night Court
Phil Sanders → Will Sanders. Same actor (William Utay), character’s twin brother…develops into a true clone after the first season.
Good:
“Law and Order”
Michael Moriarty replaced by Sam Waterston
Paul Sorvino replaced by Jerry Orbach
Bad:
“Law and Order”
Jill Hennessy replaced by Carey Lowell
“Mission: Impossible”
Martin Landau and Barbara Bain replaced with Leonard Nimoy and, a year later, Lesley Warren
for a long time, I had heard nothing good about Colin Baker’s time on “Doctor Who.” I couldn’t confirm of deny it, because all I had seen were Tom Baker and Peter Davison. But, recently, I finally got a chance to see Colin Baker in action, and I found him interestingly abrasive.
Yuck! Although Phil’s passing made for a few great episodes, the introduction of Will and the Phil Foundation marked the denoument and ultimate road to oblivion for “Night Court.” In short: he stunk up the joint. The writers should have offed Will when they had the chance.
No…I think it was fine just the way it was. Nothing personal against Nicole de Boer, but the absolute last thing the story needed during the final year was a new main character that contributed nothing to the overall plot and sucked away valuable time that could have been spent further developing the other characters’ roles in the struggle. If they wanted to do storylines that didn’t involve the war, that was fine by me. But it was absoultely infuriating that so much time was spent on crappy episodes trying to add more dimensions to someone who didn’t need to be there in the first place.
Worst: Replacing Dick York with Dick Sargeant as Darrin on “Bewitched”. York was far better as physical comedy than Sargeant (which, unfortunately, led to his demise). Sargeant played the role as a smug SOB and you wanted Endora to turn him into a frog or something.
Both of the ones that popped into my mind when I read the OP have already been mentioned, but what the heck.
Best:
Coach to Woody on Cheers
Worst:
Dick York to Dick Sargent on Bewitched with a (dis)honourable mention going to Terry Farrell to Nicole de Boer on DS9. I would have given that one top honours, but I felt that no one could have replaced such a beloved character and made something of it considering where the series was at that point.