Sitcoms are aplenty on the small screen, but every once in a while, a massive show will take the world by storm. Friends was able to pull this off in the 1990s, and during the 2000s, The Big Bang Theory turned into a giant hit.

The series had memorable characters, hilarious unscripted moments, and some great cameos that helped it reach a height that few shows will come close to matching.

Unfortunately, not all the guest stars and characters that appeared on the show were great, and the fans have been vocal about the guest character they feel was the worst in the show's history.

'The Big Bang Theory' Was A Huge Hit

From 2007 to 2019, The Big Bang Theory was one of the most popular shows on TV. Created by the legendary Chuck Lorre, the show had just what fans were looking for.

Starring a talented cast of performers with names like Johnny Galecki, Jim Parsons, and Kaley Cuoco, The Big Bang Theory was able to thrive for 12 seasons, and a total of 279 episodes.

During its storied run on the small screen, the show was able to bring in fresh stories on a regular basis, and all of them contributed to the show's success. While some people do feel that the show was wildly overrated, there is simply no denying the monumental success that it was able to find during its biggest years on television.

This is a perfect example of a show that was able to hit all the right notes on a consistent basis, and one of the great things that they show was able to do was bring in guest stars and guest characters to really liven things up.

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The Show Had Plenty Of Guest Stars

One of the benefits of having a hugely popular show is that the folks behind the scenes can often lure big names to fill in as guest stars. The Big Bang Theory was able to pull this off multiple times, and fans loved seeing these popular figures appear on the show.

Bill Nye, for instance, made multiple appearances on the show.

"The Science Guy himself came on to the show in season 7 (and again in season 12), when Sheldon brought him in to get revenge on Professor Proton (Bob Newhart). Another restraining order ensued," People wrote.

Some other notable figures to appear on The Big Bang Theory include Bill Gates, Buzz Aldrin, Carrie Fisher, and LeVar Burton.

Lovers of The Big Bang Theory and Star Wars got to enjoy episodes with the aforementioned Carrie Fisher, Mark Hamill, and James Earl Jones. In fact, Fisher and Jones collided on an episode of the show, which made geek dreams come true.

"One of several Star Wars guests, Fisher appeared briefly in season 7, when Sheldon and his new friend James Earl Jones ding dong ditched her," People wrote.

All of these guest stars were cool, but some guest stars and characters just weren't quite up to snuff. One guest character is still considered the worst of the bunch.

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Some Feel That Jimmy Speckerman Was The Worst

So, who do some fans feel is the worst guest star in the show's history? Turns out, it's someone who wound up landing a role on Young Sheldon.

"The worst guest appearance which made the episode hard to watch = Jimmy Speckerman (now = Young Sheldon's Dad)," a Reddit user wrote.

Others chimed in and agreed.

"He was the person that immediately came to mind when I read the post," another user wrote.

For the unfamiliar, Jimmy was the character who bullied Leonard in high school. He was played by actor Lance Barber, who has since gone on to star on Young Sheldon, the spin-off show from The Big Bang Theory. The franchise has cast the same person as multiple characters before, but people were still surprised to see the guy that played Leonard's bully now playing Sheldon's dad.

In the same Reddit thread discussing the show's worst guest characters, there were some other picks that popped up.

"Stuart, hands down. There's so much wrong with his character and I really disliked when he became a more prominent member of the show. From the main cast I feel they've completely butchered Raj," one user noted.

Amy, Bernadette, and Lucy were a few other picks from fans of the show.

Related: Why Does Jim Parsons Hide His Teeth On 'The Big Bang Theory'?

Jimmy Speckerman might have been bad on The Big Bang Theory, but actor Lance Barber has people singing a different tune about his character on Young Sheldon.

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