Ask yourself this question: what is worst than having a show canceled or end after a good run? The answer is a replacement in the cast. Now, there are some cast changes that have made shows better, but for this list, it will be for the shows that had a great cast, but someone replaced, it can ruin the show completely. It might not be the actor’s fault for their performance, but they just could not live up to the love and popularity a leaving character left on viewers.
Replacing the actors featured on this list eventually led to some shows being canceled as a result. That is how much of an impact a show can have for just one actor leaving.
Here are twenty actor replacements that completely ruined popular TV shows.
20 Robert Patrick - The X Files
Robert Patrick replaced David Duchovny, who played a highly popular character on The X-Files, Fox Mulder. Once Robert took over as John Doggett, he did not live up to the hype the show had. Viewers tuned out and it changed the show completely.
19 James Spader - The Office
Once Steve Carell moved on to other projects, there had to be someone to fill his role in The Office. James Spader did that and he did it well... just he is not Steve Carell. Even though the show did not cancel once James took over, it just did not have the same spark as Steve.
18 Billy West - The Ren & Stimpy Show
John Kricfalusi is the creator of the Nickelodeon classic, The Ren & Stimpy Show. He also provided the voice of Ren, who had such charm and likability. However, John was going through a sour relationship with story editor Mitchell Kriegmann. Billy West would take over as Ren, and despite his best efforts, he was not John.
17 Julia Duffy - Designing Women
This show was a victim of replacement after replacement in Designing Women. It was said by Delta Burke that producer Harry Thomason would scream at her and others. Once she left, she was replaced by Julia Duffy. Strangely enough, Duffy would also be replaced and would lead into a spiral of cancellation.
16 Jon Lovitz - NewsRadio
NewsRadio was positively received but did not attract a lot of viewers. It also did not help that Phil Hartman's sudden passing alongside his wife happened. Instead of ending the show, Jon Lovitz took over. Despite his comedic talent, he could not carry the show.
15 Tom Reilly - CHiPs
Cop shows were rising in popularity in the late 70s and early 80s, CHiPs being one of them. Erik Estrada and Larry Wilcox were entertaining and fantastic as the leads. Unfortunately, both left the show, but the damage was done when Tom Reilly replaced Larry.
14 David Spade - 8 Simple Rules
This show was a hit mostly thanks to John Ritter. Sadly, during the second season, he fell ill on set and passed away. David Spade would fill a part that John left behind. While David has comedic talent, he could not hold the show's success. He was not the only one.
13 James Garner - 8 Simple Rules
Along with David Spade, James Garner also became part of 8 Simple Rules. He played Grandpa Jim and just like David, he could not help bring the show to continue on. The show would only last for three seasons.
12 Kerry Bishé - Scrubs
Scrubs was a near-perfect show for being a comedy and drama about medical interns. It was nominated for Emmys to boot. Zach Braff left the show to focus on other projects, leaving Kerry Bishé to take over. It did not last long as the ninth season would be its final.
11 Christopher Mayer - The Dukes of Hazard
Luke Duke was the staple of The Dukes of Hazzard. He was charming and helped make the show work. His actor, Tom Wopat would still be in the show's fifth season as a recurring character with Christopher Mayer being his replacement. It just did not sit well with viewers at all.
10 Anyone - American Idol
In all honesty, no judge after Simon Cowell, Paula Abdul, and Randy Jackson can make American Idol the reality competition show that it is (or once was). Once Paula first left, the show started to slowly lose Simon and Randy. For one instance, while she is cool, Ellen DeGeneres did not make sense as a judge.
9 Janina Gavankar - Sleepy Hollow
Another cop show, another replacement. Sleepy Hollow has Abbie Mills played by Nicole Beharie and was the star. Her character would be written off while Nicole left the show. Her replacement was Janina Gavankar and there was just no hope for the show afterward.
8 Paget Brewster - Community
While there were other actor replacements in Community, we decided to feature Paget Brewster. Alongside Keith David, Community would not have the same charm the original cast had during its first few seasons. This did not earn enough revenue for Yahoo!, who was streaming the show at the time.
7 Charlie Sheen - Spin City
Michael J. Fox was not at fault for leaving Spin City, as he was diagnosed with Parkinson's Disease. Since canceling the show was not an option apparently, he would be replaced by Charlie Sheen. It also changed in tone with being a romantic comedy with his and Heather Locklear's characters.
6 Bronson Pinchot - Step By Step
A show about single parents raising their children and then getting married was something fresh during Step by Step's run. One of the cast members, Sasha Mitchell, was arrested for domestic violence and was replaced by Bronson Pinchot as Jean-Luc Rieupeyroux. It was understandable yet disappointing at the same time since Sasha played a fan favorite.
5 Diana Muldaur - Star Trek: The Next Generation
Gates McFadden was just brilliant for her role in Star Trek: The Next Generation. Sadly, she was going through tension with another actress, so she was replaced by Diana Muldaur. It did not feel natural for her being in the main cast and amazingly brought Gates back in for season three.
4 Josh Meyers - That 70s Show
Once Topher Grace left the show, things were going downhill. It would be out of place to simply have the character be offed, so the writers claimed Topher's character moved to Africa. His replacement was Josh Meyers and did not have time to have viewers warm up to him.
3 Ashton Kutcher - Two And A Half Men
Funny how Charlie Sheen was replaced by someone in another show, as he left Two and a Half Men. Ashton Kutcher replaced him and it was not welcomed with a lot of positive reception. He might be a good actor, but Ashton just missed the mark compared to Charlie.
2 Donovan Patton - Blue's Clues
What made Blue's Clues so memorable and enjoyable was the host Steve Burns. He had such charisma that it was why the show was so successful. Unfortunately, Steve was getting older and a new host had to take over. Donovan Patton took over, but it was not enough to continue the show, as it was canceled.
1 Dick Sargent - Bewitched
Perhaps one of the most infamous actor replacements, it was a shock, but understandable reason for Dick York to leave the show, as he had a severe back condition. Dick Sargent replaced him as Darrin, and while he did a decent job, there was something about York's portrayal that "changed" the character Darrin.