For an insular group of nerds, the characters of The Big Bang Theory sure have an impressive social circle. How many of us got to play “Words With Friends” with Stephen Hawking? Or can claim Wil Wheaton as a mortal enemy?

With the show’s influx of celebrity guest stars, it’s easy to forget about some of the supporting characters not played by household names. That’s all the more reason to remember them because it’s solely their talent that brings the laughs, not recognition. Plus, being able to hold your own in the company of such a stellar cast takes some pretty fine comedic chops. Here is Big Bang Theory: 10 Most Underrated Supporting Characters.

Kurt

Kurt is one of the worst human beings/evil giants to ever walk the face 0f the Earth. However, this also makes him a valuable character. There’s a difference between loathing a character and loathing their presence. A story is infinitely more fun when there is somebody to hate. The only downside to Kurt is that he never gets his comeuppance. Every one of his appearances sees him humiliating Leonard.

However, Kurt still serves an important function. He’s the impetus for Penny reevaluating the sort of men she dates. It’s a slow process - painfully so if you’re Leonard - but Penny determines that a musclebound bully isn’t worthy of her love.

Captain Sweatpants

Some of the most fascinating people are those whom we see on a regular basis but know precious little about. Captain Sweatpants is the enigma of the Big Bang universe. Both his name and backstory are unknown, but the gang can always count on his presence at Stuart’s comic book store.

When a person is a mystery, there’s usually a sexy allure about them. That’s what makes Captain Sweatpants so hysterical. There couldn’t be anything less sexy than a guy who wears a superhero T-shirt firmly tucked into a pair of gray sweatpants, especially one who is known to “touch all the cheese” at social gatherings. Is Captain Sweatpants an incredibly pathetic person, or is he actually living his best life? We’ll never know, and we like it that way.

Missy Cooper

Nobody’s surprised to hear that Sheldon is the black sheep of his family, but it’s even more humorous to see the differences between him and his regular twin sister Missy. She may not be nearly as intelligent as “Shelly,” but Missy is warm, friendly, and capable of carrying a conversation.

Missy’s introductory episode is pretty cringy. The guys vie for her attention with all the social grace of the suitors in The Odyssey. Leonard even convinces Sheldon that it’s up to him to determine the most suitable partner, basically calling Missy his property. Exactly what century do these guys think they’re living in? But it’s because of their chauvinism that Missy is able to shine. She puts them all in their place, giving Shelly a stern reminder that the only one in charge of who Missy dates is Missy herself. Darn tootin'.

Bert Kibbler

We love Bert, almost as much as he loves rocks and minerals…and that’s saying something. Bert is a gentle giant of a geologist who is sweet on Amy. As much as she and Sheldon are a fan favorite couple, they’re not always relationship goals. Sheldon is frequently dismissive of Amy’s needs, so we can’t help but wonder what the future would look like if she returned Bert’s affection? Probably not much more than a whole lot of rocks and minerals shows, but it’s still amusing to think about.

Whether it’s with women or a Vespa, bad luck sticks to Bert like glue. But he never gives up and that’s what makes him adorkable.

Stephanie Barnett

Anyone involved in the crashing of a Mars rover, even indirectly, deserves to be remembered. Like many of Howard’s pick-up attempts, his efforts with Stephanie go south in a spectacular fashion. Especially because she winds up dating Leonard.

It appears that almost all the guys are taken with Stephanie’s amiable charm, including the hard to please Sheldon. His attempts to keep Stephanie attracted to Leonard end white asparagus, vomit, and a trip to the hospital.

Sadly, Stephanie does a total 180. She goes from Dr. McCoy potential to creepy-clingy in the span of two episodes. After her Jekyll-Hyde switch, she’s never heard from again. For such a fun character, it’s a rather unsatisfying ending.

Mike Rostenkowski

Bernadette is another character who seemed to undergo a personality transplant. Originally, she’s a sweetheart who takes everything quite literally but over time, Bernadette becomes a militant, hyper-competitive pit bull. It’s jarring for the audience but upon meeting her dad Mike, it almost makes sense.

Other than the height disparity between father and daughter, Mike provides a comedic contrast to Howard, his future son-in-law. Howard’s a goofball and Mike is no-nonsense. He’s both a metaphorical and physical brick wall that Howard can’t seem to break through, until the men bond over a mutual desire to not go on a fishing trip. As Mike is responsible not just for the comic treasure that is Bernadette, but several laughs in his own right, he’s worthy of recognition.

Eric Gablehauser

Season 2 appears to be quite the black hole for solid supporting characters. It’s where Kurt, Stephanie, and Dr. Gablehauser all make their unceremonious final appearances. Dr. Gablehauser is the smarmy head of the Physics Department at Caltech, where the guys work. He belittles Howard’s lack of academic credentials and doesn’t take Sheldon seriously.

Dr. Gablehauser also isn’t coy about the fact that he is in the business of making money, not contributions to science. These reasons set him up to be a formidable antagonist to the gang, but alas, the show chose not to pursue his character. It’s a disappointment, especially considering his brief romance with Mary Cooper, a pairing that could have quite possibly made Sheldon’s head explode.

Lucy

Lucy wasn’t just the best of Raj’s love interests; she was one of the greatest supporting characters on the whole show. For all its dated jokes and storylines, The Big Bang Theory bravely explored the various manifestations of social anxiety in a number of characters. It’s through this mutual anxiety that Raj and Lucy are able to forge a romantic connection. Lucy has a tendency to get overwhelmed on dates and sneak out via a washroom window. Most would dismiss this as incredibly rude, but Raj is able to understand and even empathize with her.

Unfortunately, social anxiety also leads to the demise of Raj and Lucy’s relationship, as Lucy finds Raj putting too much pressure on her to step outside her comfort zone. While it’s sad to see Lucy go, at least she leaves on realistic terms as opposed to disappearing into the ether.

Zack Johnson

The “dumb character” always runs the risk of being flat and one-note, but Zack’s character has added layers, and it’s not just because he can’t figure out how a thermostat works. The athletic Zack legitimately wants to fit in with Leonard and the guys. This is a fresh reversal on the stale trope of the nerd wanting to fit in with the jocks. What’s also fascinating is that the guys pounce on the opportunity to mock Zack’s intelligence, until Penny points the finger at them, calling them bullies. It’s always a treat watching characters grapple with flaws they’re unaware of.

Zack may not be as popular as other recurring characters like the moms or Bob Newhart, but he pops in and out of the series up until its conclusion. We thank him both for the laughs and inventing the term “appeteasers”.

Leslie Winkle

Who says female nerds can’t have a sex drive? Before Bernadette and Amy arrived on the scene, there was Leslie Winkle. Dry and acerbic, Leslie is the perfect counterpart to the bubbly Penny. Sure, her rivalry with Sheldon gets a little old, but Leslie’s sexcapades are beyond entertaining. Her cries of amorous passion come out more as sarcastic declarative statements. “Oh, Leonard, you magnificent beast,” she deadpans. The show’s early days were light on female-driven humor, so Leslie is a welcome addition.

Also, when she switches gears to monogamy, she provides excellent conflict between Leonard and a jealous Penny. Who doesn’t love a love triangle? Leslie’s raunchiness even makes Howard look like a prude. Howard.

For whatever reason, Leslie abruptly departed from the show. She reappeared for the 200th episode but deserved much better than disappearing with her Season 2 compatriots.