With The Big Bang Theory winding down its 12th and final season this year, a television era has come to an end. Beloved by audiences and critics, the show has dominated pop culture for over a decade with its iconic lines, laugh-out-loud humor, and, of course, loveable and (sometimes extremely) relatable characters. From Jim Parsons' career-defining performance as Sheldon Cooper to former 8 Simple Rules star Kaley Cuoco's run as Penny, the show is full of unforgettable characters that we'd all like to hang out with.
However, it's not just the main cast that helps make the show, but its plethora of guest stars as well. While references are constantly made to celebrities of all kind (some of which never appear on the show), the series holds the distinction of having various stars from not only movies and TV, but science as well. From the late Stephen Hawking's recurring role as himself to the alternate version of Star Trek actor Wil Wheaton, the show is remembered by many for its large variety of star power.
It seems like the cast enjoys the show just as much as fans do, as they are constantly giving interviews of the fun, wacky, wonderful, and unforgettable times they had on the set. Unfortunately, as noted in the title, one guest star was not a big fan of their time on the show.
Here is the 1 Actor Who Regretted Being On The Big Bang Theory (And 19 Who Adored It).
20 Adored: James Earl Jones
Distinguished actor James Earl Jones may primarily be seen by many as a Star Wars icon, but his surprisingly hilarious sense of humor has also earned him the title of a Big Bang Theory icon. He plays himself in the season seven episode "The Convention Conundrum". What started out with Sheldon simply approaching him to be a part of his personal comic-con turns into a crazy night for the two, with them doing everything from singing karaoke to ding-dong-ditching Carrie Fisher (who also appears in a standout cameo).
In a behind-the-scenes interview, viewers can tell Jones had fun on the show, who admitted it was a "big thrill" to work with Jim Parsons. It looks like Darth Vader really is nicer than we thought.
19 Adored: Jerry O'Connell
First appearing in Young Sheldon, George Cooper Jr. has established himself as his younger brother's opposite, with a low intelligence and constant desire to bully him. So, fans were probably wondering if he would ever appear in The Big Bang Theory. Eventually, in season 11's final episodes, fans not only got to see where George (now played by Jerry O'Connell) ended up, but also see the brothers making amends with each other in time for Sheldon's wedding.
"It's so fun to play a non-nerd around all those nerds, and just unabashedly make fun of them for being nerds," O'Connell told Digital Spy. He also expressed his desire to reprise the role, and since he was brought back for this season's "The Tam Turbulence", here's hoping we'll see more of George before the series wraps up.
18 Adored: Neil deGrasse Tyson
When he's not debunking science myths, esteemed astrophysicist Neil deGrasse Tyson is overseeing the Hayden Planetarium, hosting science programs, and serving on The Planetary Society. For a while, however, he sought a different role: a guest spot on The Big Bang Theory.
"We've had the experience a couple of times of people forwarding fan mail that was sent to them, suggesting that they would be a good fit on The Big Bang Theory and saying, 'Well, look, it's not coming from me,'" co-creator Bill Prady told Digital Spy. "I will absolutely not embarrass the head of the Hayden Planetarium in New York City by saying who that might've been." Thankfully, the creators fulfilled Tyson's wish, and he ended up appearing twice in the series: once in season four's "The Apology Insufficiency" and again in the season 12 premiere.
17 Adored: Kate Micucci
Sometimes, we just need to find someone with similar issues to our own, which is exactly what Raj did when he met Lucy back in season six. Also dealing with social anxiety, Lucy (played by comedian Kate Micucci) was able to connect with Raj on a deeper level than other women (even though she was ultimately too shy to get involved in his personal life). Also, even though their relationship didn't last, her time in Raj's life led him to finally talking to Penny without alcohol, making her an important part of Raj's character arc in the series.
"It's been a dream to do scenes with Kunal," Micucci revealed to THR. Interestingly, Micucci originally auditioned for the role of Amy Farrah Fowler.
16 Adored: Bob Newhart
Golden Globe winner Bob Newhart may owe his success to his high-selling comedy albums and long-running sitcoms, but he owes his first Emmy win to The Big Bang Theory. As a recurring guest on the series, Newhart plays Arthur Jeffries, a childhood TV icon of Sheldon and Leonard's who goes by the name of "Professor Proton" while performing his science show for children.
Newhart told THR that his two conditions for playing the character were making the role "semi-recurring" and filming his scenes in front of a live audience. Once this was done, Newhart said doing the show made him feel like he was "going back in time" to his early sitcom years. While the character passed away in season seven, Newhart continues to talk with Sheldon as a ghost, as well as entertain his younger self on Young Sheldon.
15 Adored: Summer Glau
As a science fiction icon, actress Summer Glau is known for multiple dramatic TV roles, including River Tam on Firefly and Cameron Phillips on Terminator: The Sarah Connor Chronicles. So, it was only a matter of time before she showed up on The Big Bang Theory.
Appearing in season two's "The Terminator Decoupling", Glau played herself on a train headed to San Francisco, which the four guys were also on. Along the way, everyone (except Sheldon) attempts to make passes at her, with little success overall. However, when asked about her time on the show at the San Francisco Comic-Con in 2017, Glau revealed that she was actually nervous about meeting the crew and how different the show was compared to her usual roles. Thankfully, the actors (unlike their characters) were all "really cool" with her and she ended up having "a great time."
14 Adored: Johnny Galecki
Ah, Leonard Hofstadter. Despite trying to be the group's voice of reason, he still falls victim to the same nerdy hijinks that other guys do, and we love him all the more for it. Though he was originally best known for his recurring Roseanne role as David (or Kevin) Healy, Galecki's life was changed forever when he earned the starring role on The Big Bang Theory. As one of the show's most likeable characters, it's no wonder Galecki has been nominated for both an Emmy and Golden Globe.
When Galecki was interviewed by People, he admitted that the end of the show would be "very bittersweet." He went on to say, "We're a true family there, absolutely. It's just been such a bonding experience for all of us."
13 Adored: Eliza Dushku
When Howard needs security clearance to work on a project with the Department of Defense, an F.B.I. agent is sent to interview the other guys about his trustworthiness who just so happens to be played by fan-favorite Buffy the Vampire Slayer actress Eliza Dushku. From Leonard's unsuccessful pickup attempt to Raj's fear of being deported, the laughs keep coming in season four's "The Apology Insufficiency" as the guys prove to Dushku just how crazy the job can be sometimes.
When discussing her preparation for the role with TV Guide, Dushku revealed that she researched each of the characters on Wikipedia in order to go in just as prepared as a real F.B.I. agent would be, resulting in a "very natural and very fun" role.
12 Adored: Simon Helberg
Though he can come off as mysognistic at times, Howard Wolowitz is as important to the show as anyone. Winning a Critic's Choice Award for the role in 2013, Simon Helberg has dominated the screen with his one-of-a-kind performance, and, as he revealed to ScreenCrush, the addition of Melissa Rauch's Bernadette only helped strengthen the character.
"...All of a sudden it started to unlock a lot of these different layers to Howard, to see him be a bit more sensitive, and to cut through that sleaze and get to the heart of him," Helberg said. It will certainly be hard to see him go, and Helberg definitely feels the same, as he referred to the show in a HuffPost interview as "a place to kind of feel like you're not alone with your geekiness."
11 Adored: Mike Massimino
As everyone was made aware of back in season six (mostly due to Howard's multiple reminders to everyone), Howard took a trip to the International Space Station as a payload specialist. Sharing the expedition with him were fictional astronaut Dimitri Rezinov (played by Pasha Lychnikoff) and real-life professor of mechanical engineering and former NASA astronaut Michael Massimino.
While both astronauts give Leonard a hard time while in space, it's Massimino that stands out, who gave Leonard the nickname "Froot Loops" after overhearing a conversation between him and his mother. Appearing in six episodes throughout seasons five through eight, Massimino shined as a painful but hilarious reminder of Howard's time in space. While he told collectSPACE following season five that he wouldn't be quitting his day job, he admitted the show was "a fun thing to do" and "good for NASA."
10 Regretted: Charlie Sheen
Though many celebrities loved their time on The Big Bang Theory, there is one who probably wishes he not only had never guest-starred, but also never met creator Chuck Lorre in the first place. What man could have had such a horrible time working with TV's "King of Sitcoms?" None other than Golden Globe winner Charlie Sheen.
By now, everyone is aware of Sheen's firing from Two and a Half Men in 2011. However, he also had more than a few choice words for Big Bang during an interview with The Guardian. "It's a stupid show and it's just lame, about lame people," he said. Fortunately for Sheen, he only had a quick cameo in season two.
9 Adored: Wil Wheaton
Perhaps no other recurring guest star has made the biggest impact on The Big Bang Theory than Sheldon's former arch-enemy Wil Wheaton. Yep, the actor behind Star Trek: The Next Generation's Wesley Crusher has not only managed to craft a perfect foil for Sheldon, but also a likeable alternate version of himself for pop culture fans. However, Wheaton has discussed his initial issues with the character, which took him around five years to separate from his real self.
Thankfully, according to his interview with The Spectrum, he has accepted the character as possibly "the only role in my career where the feedback has been universally positive" and now considers the show to be one of his favorites to work on.
8 Adored: Kevin Sussman
First appearing in season 2, Kevin Sussman's Stuart became a love interest of Penny's, only for their relationship to end after she called him "Leonard." However, his luck eventually changed, as he became an official part of the group during Howard's time in space and has since gone on to care for Howard's mother and baby, as well as meet his potential soul mate, Denise, in season 11. It's quite the character arc for someone who started out just selling the guys comics.
"...It's been overall an amazing and positive experience, working with everybody on the show," he told GameZone at Comic Con Africa in 2018.
7 Adored: Mayim Bialik
Ever since fans were first introduced to Sheldon Cooper, many were wondering if he would ever find a special someone. However, fan wishes were answered in the season 3 finale, where, with the help of Raj and Howard, Sheldon met his future wife, Amy Farrah Fowler. It didn't take long for fans to see just how much the two had in common, from their vast scientific interests to their shared social awkwardness and anxieties.
Since then, former Blossom star Mayim Bialik has expanded the role of Amy to be tighter with the group and closer to Sheldon, and her four Emmy nominations and two Critic's Choice Award wins are evidence of this. When she learned the show was ending, Bialik expressed her love for Amy on her website, Grok Nation, and how "very sad" it was to see her story conclude.
6 Adored: Kunal Nayyar
Despite having the shyest personality and the worst luck with women, Kunal Nayyar's character of Rajesh "Raj" Koothrappali has always brought some of the series' biggest laughs and has earned a multitude of fans. As for his love life, many fans are hoping that he'll have an established true love by the end of this season, and it thankfully looks that way due to his acceptance of Anu's proposal (Nayyar, meanwhile, has been married to Miss India 2006 since 2011).
Way back in 2008, Collider sat down with Nayyar to discuss his experience on the show's first season, and he humbly admitted that the greatest part of it was "the cast who I love and the producers, our directors, and we're having such a good time because we love each other and that speaks to the amount of fun we're having."
5 Adored: Billy Bob Thornton
Penny has drawn the attention of several men over the years, but, while she usually ended up dating them at some point, one man in particular was just a bit too creepy for her taste -- and Bernadette's and Amy's. In season eight's "The Misinterpretation Agitation", Oscar-nominated actor Billy Bob Thornton assumed the role of Dr. Lorvis, a urologist who develops feelings for any woman who is nice to him. Also, given how flirty Penny can be, it's no wonder she became a subject of his interest.
Since she was engaged to Leonard at the time, this naturally never went anywhere, but Thornton's performance left an impact on the show's crew. "He has said he had a wonderful time," showrunner Steve Molaro told EW. "All of us just fell in love with him. It was a magical week."
4 Adored: Laura Spencer
As another of Raj's memorable romances, Emily Sweeney holds the distinction of appearing in four seasons and even being promoted to a series regular for a time. Played by Laura Spencer from seasons seven through 10, Emily, a dermatologist Raj meets online, was a unique member of the cast due to her love for the macabre and tension with Penny (since she and Raj have kissed before). Spencer revealed to Gotham that she shares some similarities with the character, though, thankfully, none of the dark traits.
"I think her sensitivity to Raj and her genuine interest in him, his quirks are similar to my own," she said. "But, as far as all the dark, little weird elements of her personality...the writers have gotten very creative with that and I think it's really funny because that's not really how I am."
3 Adored: Kaley Cuoco
More than just "the girl next door," Penny's role as the overall voice of reason has left an impact on both the cast and audiences. After ending her time on 8 Simple Rules, Kaley Cuoco moved on to the starring role that would define the rest of her career. Also, if her interview with ET at the 2019 Golden Globes is any indication, it looks like she is just as upset as fans are that the show is almost over.
"I don't wanna leave, I don't wanna leave," Cuoco said. "'I said it. I don't wanna leave!" Cuoco then suggested that the show should be rebooted in the near future, and she would be "fine with that." Even if we never see Penny again after this year, at least we'll remember Cuoco's great character and her love for the show.
2 Adored: Aarti Mann
Before ending up with Penny, some wondered if Leonard's true soulmate was Raj's younger sister, Priya. Well, no one wondered about it, but it was still interesting to think about. She was a recurring character in seasons four and five. Priya's intelligence leveled closer to Leonard's, but her jealousy over Penny made her very unlikeable. Thankfully, she eventually moves away and Leonard realizes she's not the one for him (especially after finding out she was unfaithful to him). Despite playing an unlikeable antagonist, however, Mann loved playing Priya, as evidenced by her The Post and Courier interview.
"I would love to come back and see where it goes with Leonard and Priya," she said before revealing that she wasn't sure if she would return for season five. It looks like she got her wish, but whether it was what she wanted for Priya is another question.
1 Adored: Jim Parsons
Over these past 12 years, Jim Parsons has established his career-defining character with the multi-Emmy-winning role of Sheldon Cooper. Despite his initially non-social personality, Sheldon never failed to keep his friends by his side and keep audiences laughing every week. Though the show is almost over, Parsons made it clear to Variety back in 2016 that once it ended, he would focus more on what the show accomplished than missing it.
"I really feel like the way [the show] is going, all I'll feel like is, 'We did it! We did that show,'" he said. Parson made the decision to not return for a 13th season since he thought that it was the appropriate time to end the series. He then proceeded to pen an emotional letter for his fans on Instagram.
Are there any other Big Bang Theory actors who regretted or adored the expereince? Let us know in the comments!