Summary

• The Big Bang Theory ended after 12 seasons and 279 episodes, but some installments stand out for their hilarious jokes and emotional moments.
• "The Thanksgiving Decoupling" showcases Sheldon's emotional side as he opens up about his father, providing new depth to his character.
• "The Opening Night Excitation" is one of the show's best episodes, as Sheldon's non-sexual character takes a huge leap by considering having sex with Amy.

The incredibly popular sitcom The Big Bang Theory came to an end in 2019, bringing the show to a close after an incredible 12-season run with some truly outstanding episodes. The show follows a group of scientist friends with a variety of nerdy hobbies: Leonard (Johnny Galecki), Sheldon (Jim Parsons), their neighbor Penny (Kaley Cuoco), and their other friends. The Big Bang Theory also saw such success that the last season overlapped with the first season of its spinoff, Young Sheldon, which follows Sheldon growing up in Texas as a child genius.

Since The Big Bang Theory's ending, the cast has continued to expand upon their prominent careers but are still best ed for their roles in the show. With a whopping 279 episodes under its belt, The Big Bang Theory shocked fans by ending after season 12. The bingeworthy show had plenty of episodes that could be considered its best, but some stand out more than others.

15 The Justice League Recombination

Season 4, Episode 11 (2010)

Season 4's "The Justice League Recombination" is one of the best The Big Bang Theory episodes for several reasons. Firstly, it celebrated the gang's love of all things superhero when they decide to enter a costume competition at Stuart's comic book store. Seeing Howard, Raj, Leonard, and Sheldon argue over who gets to be which superhero is funny enough, but the hilarity gets significantly upped when Penny's dimwitted boyfriend, Zack, s to play Superman.

The episode is filled with several important emotional moments between Leonard and Penny too, with Penny revealing that she only agreed to date Zack to ensure she wasn't alone on New Years Eve. However, while episodes featuring Zack are always funny, Sheldon impersonating The Flash is easily the highlight of the episode, with Jim Parson's showing he's just as good at physical comedy as he is verbal delivery.

14 The Roommate Transmogrification

Season 4, Episode 24 (2011)

Season 4 was truly a high-point for The Big Bang Theory, as another one of the best episodes in the show, "The Roommate Transmogrification", came as the season finale. "The Roommate Transmogrification" sees Raj move in with Sheldon, so Leonard can live with Priya, and the results are exactly what viewers would expect. Sheldon isn't happy with his new roommate at all, at least at first, though he soon starts to see the benefits (such as Raj arranging their takeaway meals like fancy dinners).

However, this episode of The Big Bang Theory is so memorable because, right at the end, Penny and Raj wake up together after an evening drinking wine. Of course, it later emerges that Raj and Penny simply shared the bed and nothing actually happened, though it took a long time for The Big Bang Theory to reveal this. The episode features many hilarious moments between Raj and Sheldon, but there's an equally funny side-story with Howard and Bernadette too involving her making more money than he does.

13 The Good Guy Fluctuation

Season 5, Episode 7 (2011)

The Big Bang Theory season 5 episode "The Good Guy Fluctuation" saw Leonard meet Alice, a comic-book artist who could quite possibly be the woman of his dreams. They share an instant connection, but unfortunately for Leonard, he is still in a relationship with Priya. Alice finds out about Priya only after she and Leonard had kissed, ending the potential relationship before it had even began. What's worse, at the end of the episode, Leonard finds out that Priya has cheated on him.

However, while this is defintiely an interesting moment for Leonard, it's the side-story with Sheldon that truly makes "The Good Guy Fluctuation" one of the best The Big Bang Theory episodes. Sheldon gets pranked by Howard and Raj early on in the episode, and so sets out to prank the rest of the gang. Every attempt fails and backfires on Sheldon spectacularly, making for some hiilarious and unforgettable moments.

12 The Scavenger Vortex

Season 7, Episode 3 (2013)

Raj has a penchant for parties and organized fun, and this comes to the fore in season 7's "The Scavenger Vortex". This is one of the best The Big Bang Theory episode because of Raj's scavenger hunt, during which he pairs off the rest of the gang in unusual couplings. This makes for some great moments between characters who don't usually spend much time alone together on-screen, giving a unique take on the group dynamics.

It's the pairing of Penny and Sheldon that makes for many of the funniest moments in "The Scavenger Vortex", and the episode is a key one in the development of their friendship.

Amy and Howard find that they have a shared love of Neil Diamond, for example, and Bernadette borderline-bullies Leonard due to her competitive nature. Of course, it's the pairing of Penny and Sheldon that makes for many of the funniest moments in "The Scavenger Vortex", and the episode is a key one in the development of their friendship.

11 The Tangerine Factor

Season 1, Episode 17 (2008)

"The Tangerine Factor" was the season 1 finale, and stands as one of the best episodes of The Big Bang Theory for a reason — after a whole season of will-they-won't-they, Penny and Leonard finally go on a date. It's a terrible breakup that makes Penny agree to the date in the first place, which leads to some confusing feelings for her. Leonard is, of course, absolutely terrified the second Penny says yes. What makes their dilemmas so funny, however, is who they turn to for advice — Sheldon Cooper.

For his part, Sheldon is completely and hilariously exasperated by their constant bothering him for advice. He has much more important problems, namely that his favorite Chinese restaurant, Szechuan Palace, is ing off orange chicken as tangerine chicken. It was a strong end to the show's first season, and even after hundreds more episodes "The Tangerine Factor" is still a perfect example of everything that made the sitcom so popular.

10 The Hawking Excitation

Season 5, Episode 21 (2012)

Many episodes of The Big Bang Theory feautre guest stars that align with the nerdy interests and intellectual lifestyle of Leonard, Sheldon, Howard, and Raj. However, one of the most memorable was the late Stephen Hawking in season 5. In "The Hawking Excitation," Stephen Hawking visits the university as a visiting lecturer, and in typical Sheldon fashion, he manages to mess up his chances of meeting the scientific legend.

To make it up to him, Howard (Simon Helberg) sends Sheldon off to perform ridiculous menial tasks for him. "The Hawking Excitation" is full of hilarious moments from Jim Parsons as Sheldon, including his reaction to seeing Hawking for the first time. However, the episode doesn't quite tick enough of the relevant boxes to land at the top of the list of best episodes.

9 The Lunar Excitation

Season 3, Episode 23 (2010)

Sheldons's eventual wife Amy Farrah-Fowler became a fan-favorite character after she debuted in season 3, so it's little surprise that her introduction led to one of the best episodes of The Big Bang Theory. In "The Lunar Excitation," the Big Bang Theory gang gathers on the apartment roof to perform a lunar ranging experiment. This episode kicks off the relationship between Sheldon and Amy (Mayim Bialik).

Amy and Sheldon have a hilarious first date, and the similarities between the two characters see an interesting shift in The Big Bang Theory's format going forward. "The Lunar Excitation" contains some great jokes from the entire cast, but Bialik's performance sets up Amy's character beautifully, providing an almost caricature replication of Parsons' performance as Sheldon. Penny's reaction to learning that the rest of the gang have taken to referring to the pair as "Shamy" is a laugh-out-loud moment too.

8 The Robotic Manipulation

Season 4, Episode 1 (2010)

One of the most outrageous characters in the show, especially in early seasons, was Howard, though easily his most memorable moment came in The Big Bang Theory season 4 episode "The Robotic Manipulation, which stands as one of the best because it effectively utilizes his background in engineering with hilarious results. "The Robotic Manipulation" finds Howard borrowing a robotic arm from the Jet Propulsion Laboratory.

After a series of events, Howard ends up with it connected to a rather unfortunate part of his body. "The Robotic Manipulation" offers a great performance from Simon Helberg, really cementing Howard's character in the earlier seasons of the show and making the development seen in later seasons even more impactful. Although "The Robotic Manipulation" is hilarious, it doesn't warrant the title of The Big Bang Theory's best episode, and its main joke about Howard could be considered a little too forthright.

7 The Thanksgiving Decoupling

Season 7, Episode 9 (2013)

Sheldon is the center of many of the best The Big Bang Theory episodes, and season 7's "The Thanksgiving Decoupling" includes one of his funniest scenes. "The Thanksgiving Decoupling" sees the usually straight-thinking Sheldon Cooper getting drunk, resulting in some hilarious and emotional moments for the character. Sheldon is distracted by Bernadette's father, Mike (Casey Sander), and the two bond over football.

However, alcohol doesn't just lead to funny moments for Sheldon, as "The Thanksgiving Decoupling" includes plenty of emotional ones too. Sheldon reveals more about his own father, who was a high school football coach during his childhood. Sharing several beers with the older man, Sheldon talks openly about George Cooper Sr.'s death, prompting the episode's most heart-wrenching moments. Sheldon litters details of his family's life throughout The Big Bang Theory, but "The Thanksgiving Decoupling" allows the character to fully open up about his past.

6 The Opening Night Excitation

Season 9, Episode 11 (2015)

Just as the introduction of Amy on The Big Bang Theory led to one of its funniest episodes, so do did a key milestone in their relationship — when he finally considered becoming physically intimate with her. "The Opening Night Excitation" brings about huge character development for Sheldon. Stressed about picking a birthday present for Amy, he tells Penny and Bernadette (Melissa Rauch) that he is considering having sex with her.

As Sheldon had up until then been a non-sexual character, the two women are completely taken aback by how casually he approaches the topic, resulting in a hysterical moment for all. Not only is "The Opening Night Excitation" one of the show's best episodes because of the huge changes seen for Sheldon, but it also contains one of Fowler's funniest moments: Amy giddy with excitement over what is going to happen and enthusiastically shouting about getting waxed.