The Big Bang Theory’s upcoming 12th season, which will start September 24, 2018, will sadly be its last.
The CBS sitcom about a group of highly intelligent yet socially awkward physicists who work at Caltech, their equally oddball and nerdy friends and colleagues, and the pretty waitress/aspiring actress who moves in across the hall, has consistently been ratings gold for the network, though viewership began to dip slightly in the last season. Its five main cast members, Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, and Kunal Nayyar, are among the highest-paid actors on TV, even after agreeing to a pay cut last year in order to increase the salaries of newest cast members Melissa Rauch and Mayim Bialak. The series has received multiple Emmy nominations, and Parsons has won four times for his role as the awkward Sheldon.
But alongside its fantastic cast, the show, which highlights every part of “geek culture,” from comic books to Star Wars and Star Trek, has had a revolving door of guest stars. Some have only appeared for a minute or two, while others have had recurring roles. But many of them appear as the group totally geeks out, and often reluctantly after having been approached by a starstuck Sheldon.
Here are some of the most memorable guest stars, all of whom will help this series go down as one of the funniest sitcoms of this generation.
As Sheldon’s childhood hero and inspiration, Professor Proton was the host of science-based television series in the ‘80s. Newhart has appeared five times playing the now-dejected former TV personality who makes party appearances for money. While clearly annoyed with Sheldon, Newhart’s deadpan humor is perfectly on display in the episode when, even after the character’s death, he appears in Sheldon’s dreams to reluctantly give him advice.
In a Halloween-themed episode, Aldrin is seen in a video handing out candy to kids. He grills them on their accomplishments, and makes sure they all know that he’s an astronaut. Passing out space-themed treats like Milky Way and Mars chocolate bars, he declares to one young boy: “This one’s a moonpie. I’ve walked on the moon. What have you done?”
After breaking up with his girlfriend, Howard (Helberg) daydreams while getting ready for some self-pleasuring. Katee Sackhoff appears, sprawled next to him in bed, in her Battlestar Galactica flight suit. But she’s quickly, and puzzlingly, joined by Takei. “Howard, do you have latent homosexual tendencies,” she asks, to which Howard declares an emphatic “no.” “So you say,” replies Takei in his typical whimsical style, “yet, here I am.”
Mr. Spock himself, Leonard Nimoy, didn’t actually appear in the series, though his name has come up on numerous occasions by the dedicated Trekkies. Most notably, in a Christmas episode, Penny gets Sheldon a napkin from her restaurant that was not only signed by the actor, but also had his DNA. Sheldon excitedly mulls over the idea of cloning his own version of Spock. He’ll never meet the real Nimoy, after all, since there’s a restraining order for undisclosed reasons. Nimoy’s voice also appears once as a Spock action figure. After the actor’s untimely death in 2015, his son Adam appeared in an episode alongside Wil Wheaton to interview Sheldon for a documentary.
Best known as Lieutenant Commander Geordi La Forge in Star Trek: The Next Generation, Burton has been in three episodes to date, once briefly after he arrives at (and immediately leaves) a party he was invited to on Twitter after walking in on weird shenanigans; and as a guest on Sheldon and Amy’s (Mayim Bialak’s) web show Fun with Flags. While he hasn’t yet filed a restraining order, he did appear again slamming the door in Sheldon’s face, and declaring that he “should have listened to Wil Wheaton” and bought a gate.
Like the others on the list, Wheaton plays a version of himself. As Sheldon’s frenemy, the two are often competing for attention and recognition, ribbing one another any chance they get. While he’s appeared in multiple episodes starting from the third season, Wheaton’s most recent appearances in season 11 saw him snagging the hosting gig for a reboot of Professor Proton’s show (which angers Sheldon), and getting bumped last minute by a much bigger star to officiate Sheldon’s and Amy’s wedding.
After Sheldon’s misses a signing with the famous comic book creator, Penny (Cuoco) convinces him to go to Lee’s house to meet him. Answering the door in a robe and understandably angered at the impromptu fan visit, Lee’s sarcastic invitation to Sheldon to come in and watch the Lakers game leads to the man behind Spider-Man becoming the second celebrity to file a restraining order against Sheldon.
Howard is tasked with maintaining Hawkings’ wheelchair when he visits Caltech for a lecture, and Sheldon desperately wants to get a paper he wrote into the hands of the iconic cosmologist. “It’s an honor and privilege to meet you sir,” says Sheldon, once he succeeds. “I know,” Hawking replies through his signature computer and voice box. After Sheldon realizes the paper had a mistake, however, he faints. “Great,” sighs Hawking. “Another fainter.”
Spotted in the restaurant where Penny works, the Apple co-founder compliments Sheldon’s virtual presence device. Sheldon declares that Wozniak is his 15th favorite tech visionary (hey, it’s still six spots above Steve Jobs). They bond over their hatred of turtlenecks, but when Sheldon leaves to bring his vintage 1977 Apple 2 for Wozniak to sign, the inventor whispers “nerds” to his dinner date.
Most memorable about this appearance on the 200th episode of the show, where West is paid to attend Sheldon’s birthday party as a surprise, is the hilarious discussion he has with the guys in the car on the way there about who’s the best Batman. “Even my poodles know Bale is over-rated!,” he says, ranking them from best to worst. Lego Batman is above Bale, and West is in first place above Michael Keaton, but only when you factor in humor.
In order to make Professor Proton jealous, Sheldon befriends Bill Nye, another “beloved children’s television science personality.” But it backfires when Nye declares his love to Professor Proton, saying his show would never have happened without Proton’s. Newhart’s clever response? “That’s what I told my lawyers.” Eventually, Nye becomes the third celebrity to get a restraining order against Sheldon.
James Earl Jones
Following a chance meeting in a restaurant, Jones, the voice of Darth Vader himself, bonds with Sheldon over their mutual love of Star Wars. But a fun-filled day spent together, including a visit to a carnival, strip club, karaoke club, and even a sauna, makes Sheldon realize he can’t keep up with the overly friendly actor.
In a short cameo in the aforementioned episode with Jones, he and Sheldon play the classic Nicky Nine Door childhood prank on Fisher by ringing her doorbell and running away. She opens the door in her robe, baseball bat in hand yelling “it’s not funny anymore, James!”
When Howard donates his time to a soup kitchen on Thanksgiving, he discovers Elon Musk working there, washing dishes (he got demoted from the turkey line after being “too generous with the gravy.”) They discuss Howard’s time in space, and bond over a piece of leftover pumpkin pie.
The latest to appear in the series, in the season 11 finale, Howard finds a lost dog that ends up belonging to Luke Skywalker himself, much to his shock and excitement when the actor arrives to pick up the pup. When Hamill insists on some kind of reward, Howard asks him to officiate Sheldon and Amy’s wedding. He shows up, taking the place of an insulted Wheaton, who had originally been asked to help the couple say their “I dos.”