Since its ignition in 2007, The Big Bang Theory became a huge hit, especially among comic book and sci-fi fans. One of the main reasons for the show's success is the outstanding and complex main cast. Initially featuring only four scientists and Penny, the group later expanded to include female scientists Bernadette and Amy. But since the beginning, Raj was an integral part of the show.
Repeatedly becoming a laughing stock to the other characters, thanks to his relationship struggles and his awkward social skills, Raj had many hilarious moments on the show. Whether that's his scientific discoveries or his embarrassing encounters with girls, Raj is always one to make fans laugh.
Updated on March 20th, 2022, by Lynn Gibbs: Raj Koothrappali is part of the ensemble cast that made The Big Bang Theory the success that it was. Unlike his friends, Raj was more sensitive and worked in astrophysics. He loved hanging out with Penny, Amy, and Bernadette because they always listened to his problems with women. Out of the group, Raj was the only one who didn't end up with a partner. Because of Raj's ups and downs with women, his job, and his friends, he had a couple of important episodes in TBBT.
The Collaboration Fluctuation (S10; E19)
In the 10th season, Raj was spending time at Penny and Leonard's apartment because he was saving money to be able to afford his own place. One of Raj's mistakes was overstaying his welcome because there came when Leonard became jealous of Raj and Penny's friendship.
Raj was genuinely interested in Penny's job and the two spent time together outside of work. Leonard felt left out and thought Raj should move on, but it took Raj time to pick on Leonard's cues. This episode is one of the better ones because of how funny Raj's moments with Penny were, and because he had to find his next plan for where to live.
The Santa Simulation (S6; E11)
In this episode, the guys had a full evening of Dungeons and Dragons planned while the women went out for girls' night. But when Raj's time with the game ended early, he ended up leaving the guys to spend the night in a bar with the girls.
While there, Raj bonded with Penny, Amy, and Bernadette on a deeper level. He and Amy, in particular, had a deep talk about relationships and feeling left out compared to their social circle. It was a time when Raj was the most open. It was also one of the best girls' nights because of Raj's addition.
The Pirate Solution (S3; E4)
In the third season, Raj found out his work visa had come to an end and he either needed a new job in the States or he was going to be deported. Considering how close he was with everyone, fans were heartbroken at the idea of Raj leaving the group.
In a shocking twist, Sheldon saved the day and offered Raj a job working for him. Sheldon needed help exploring dark matter and knew Raj could be that guy. Although Raj found it hard working for Sheldon, this episode showed how much his friends appreciate him and want him around.
The Confidence Erosion (S11, E10)
Season 11 was all about Sheldon and Amy's upcoming wedding. However, Raj did have a breakthrough moment with Howard.
Raj was interviewing for a side job outside of his work at Caltech but Howard wasn't being supportive. In fact, Howard's jokes were making Raj more insecure. When his interview didn't go well, Raj's parents blamed Raj's lack of confidence on the friends he surrounded himself with. It's then that Raj realized how poorly he feels around his best friend and that maybe he and Howard weren't best friends. What made this episode important for Raj was that he finally stood up for himself against Howard and took some time away from the friendship to refocus.
The Grasshopper Experiment (S1; E8)
After his parents from New Delhi get broadband for the first time, they decide to set Raj up for a blind date with Lalita Gupta, who has just moved to California. Despite going against Raj's wishes, Howard decides to set up a date for the pair at the Cheesecake Factory. What unfolds is a hilarious and messy date after the gang realizes that Raj can only speak to women under the influence of alcohol.
While practicing mixing cocktails before the date, Penny and the guys get Raj drunk. What follows is a disastrous date, a loud and obnoxious Raj, with some incredibly funny moments, including Sheldon stealing Raj's date. Because of Raj learning he can speak to women under the influence—ignoring his selective mutism—this was a big episode for him. His selective mutism was one of the saddest things about Raj and held him back from a lot.
The Griffin Equivalency (S2; E4)
In episode 4 of season 2, Raj is included in People magazine's "30 (Visionaries) Under 30 (Years of Age) to Watch" thanks to his discovery of a planetary object beyond Kuiper's belt, which he named "Planet Bollywood." Unfortunately, the fame and success all go to his head as Raj becomes incredibly obnoxious and cocky.
Whilst the rest of the gang refuses to attend the event due to Raj's cocky behavior, Penny, oblivious to his inflated ego, agrees to go with Raj, who thinks it is also a date. Raj thought the evening was going to be one of his and Penny's best moments but the opposite happened. The night unfolds with a drunk Raj who tries to make out with Penny and introduces her to his parents as his girlfriend.
The Bon Voyage Reaction (S6; E24)
Having been with Lucy for a little while, Raj wants to take things with her further and invites her to meet the gang. After initially refusing, Raj convinces her to have dinner with just Amy. During the dinner, Raj puts Lucy on the spot asking her to be his girlfriend, resulting in her going to the bathroom and never coming back to the dinner.
Unaware of his actions, Raj invites her over to Leonards's going away party, but Lucy doesn't show up, which leads to their break up. After Leonard leaves, Penny and the girls check on Raj, who unknowingly speaks to them for the first time without having anything to drink. It's a huge milestone for the character and ends season 6 perfectly.
The Wildebeest Implementation (S4; E22)
Before his breakthrough moment in 'The Bon Voyage Reaction,' Raj decided to experiment with alcohol and scientific drugs to resolve his inability to speak in front of girls. In 'The Wildebeest Implementation,' Raj was given a drug by a friend as a way to reduce his social anxiety.
After some words of reassurance from Sheldon, Raj decides to take the "next big thing." In what was a hysterical scene, Raj and Sheldon went to a coffee shop to test the side effects. To Sheldon's surprise, within minutes of talking to a girl, Raj was stripped naked in front of everyone. One would think Sheldon and Raj weren't friends because of how nonchalant Sheldon was when this happened. Regardless, it's a big episode because it shows him facing his fear of speaking to women.
The Comet Polarization (S11; E21)
In season 11, Raj decides to set up a telescope and his computer on the roof of Sheldon and Leonard's apartment building. While looking for Mercury, Penny notices something blurry in the sky. After taking a look and analyzing the picture, Raj confirms that Penny did in fact find an unrecognized comet and that they can take credit for the discovery.
However, Raj gets worse and worse when he decides to take full credit for the comet in order to avoid any professional embarrassment. This leads to an uncomfortable argument between the pair. This is an important episode for Raj because it showed conflict resolution with his friends and overcoming his pride.
The Emotion Detection Automation (S10; E14)
After a few failed relationships, Raj wonders why girls keep on dumping him. After the help of his best friend and engineer Howard, Raj speaks with his ex-girlfriends to find out why. They are joined by Lucy, Claire, Emily, and the other Emily in an attempt to help him and his romances since his previous relationships were toxic.
After the awkward conversations, Raj decides it was all a waste of time, once again being oblivious to his own problems. But, thankfully, the episode ends on an extremely funny note, where Howard suggests if he is no longer with Bernadette in 30 years, the two of them can get together. The ending was a sweet one to an episode that dissected Raj's habits.
The Roommate Transmogrification (S4; E24)
In the season 4 finale, the guys decide to have a little rearrangement of their living spaces. Leonard moves into Raj's apartment with his sister Priya, and as a result, Raj moves in with Sheldon. The episode begins as expected, Raj lays out a fancy dinner for new roommate Sheldon, much to his delight, and the guys make fun of Howard for being the only non-doctor.
But after some deep conversations, a Leonard heartbreak, and a Howard-Bernadette argument, fans wake up to see Raj and Penny in the same bed. It's a jaw-dropping and hilarious way to end the season and a big episode for Raj.
The Tangible Affection Post (S6; E16)
It's Valentine's day in season 6 and the couples of the group all have romantic plans for the evening, apart from Raj, who finds himself alone. With the help of Stuart and his comic book store, the pair decide to host a party for everyone single. After decorating the store, the singles are treated to a special and sweet speech by Raj.
After his speech, Raj meets Lucy for the first time. The pair hit it off and head out for a coffee, completely contradicting his earlier speech. Seeing this side of Raj (and the start of the Lucy era) is important for viewers.
The Thespian Catalyst (S4; E14)
When Raj was still struggling with his romantic pursuits and was found, once again, without another half, his loneliness started to create some issues. In this particular episode, in an attempt to suppress his feelings, Raj begins to daydream about Bernadette.
In his dreams, Raj willingly accepts Howard's dying request of satisfying Bernadette's sexual needs after his death. In a hilarious turn of events, which all lead to a Bollywood-style dance sequence, fans are left wondering how Raj could fall in love with his best friend's wife...
The Maternal Conclusion (S12; E22)
In one of the last episodes of the entire show, Anu is offered a job in London. Conflicted between his friends in California and the prospect of a new life in London with Anu, he decides a fresh start is what he needs and plans to move to London.
While waiting in line for the plane, Howard, in typical rom-com fashion, rushes through and, in what was a heart-wrenching and extremely sweet moment, tells him that he loves him. It was a perfect rom-com moment for Raj, who thankfully stayed in California with his friends. Because of Raj's questionable future coming up in the finale, this was an important episode for Raj.