Whether it is Sheldon pushing himself out of his comfort zone to hug Penny, or Leonard hugging Sheldon moments before his wedding, heartwarming gestures between friends are not hard to come by in The Big Bang Theory. For a show that centers around a group of socially inept young men, friendships form a crucial part of each character's arc.
The central friendship in the series between Leonard Hofstadter and Sheldon Cooper evolved over time as Sheldon became a tad more mature and Leonard knew that he would do anything for his friend in spite of how he hated him at times. But gradually other friendships such as that between Howard and Raj and Penny and Amy became vital to the storylines as well, and each came with its own set of hilarious or gently sweet moments that fans adore.
Amy Kissing Penny In The Pub
Penny and Amy had a bit of a one-sided relationship - at least at the beginning - with the latter harboring a huge girl crush on the former. The two started out on a slightly awkward note but soon they were having nights out along with Bernadette.
The scene in the season 4 episode "The Agreement Dissection" where Amy kisses Penny on the mouth is fun. It is also a defining moment in their friendship as they seem to have got past the initial awkwardness and are pretty much on their way to becoming best friends. It is also clear that her friendship with Penny will be an important relationship in Amy's life apart from that with Sheldon.
Penny Finally Calling Amy Her Best Friend
Penny finally declares that Amy is her best friend in season 11's "The Matrimonial Metric" when she realizes that she hasn't been asked to be the latter's maid of honor. Once again, this is a crucial moment in the trajectory of their friendship that had seen Penny appear a tad non-committal every time Amy called her her 'bestie'.
The scene finally marks the culmination of one of Amy's heartfelt desires, to have Penny as her best friend. This is also a moment that signifies that two women who seem to be quite different from each other could end up as each other's most trusted lieutenant.
Howard Stopping Raj At The Airport
One of the running storylines in the series was the quirky but ultimately genuine friendship between Howard and Raj. The two had a relationship that bordered on the unhealthily co-dependent, but there were still a few moments here and there that fans loved about their friendship.
When Raj decided to leave Pasadena for London to be with Anu, Howard rushed to the airport to stop him in a scene in season 12, episode 22, reminiscent of romantic comedies. Raj might not have found his lady love but his attachment with Howard was true enough.
Raj With Penny After Getting Dumped
Another beautiful friendship on the show was between Penny and Raj. Penny comforting Raj after he had just been dumped unceremoniously by a young woman named Emily, is a beautiful moment between these two friends. It was Penny who had set Raj up with Emily who unfortunately turned out to be more interested in the expensive things he bought her than in Raj himself.
Raj was understandably heartbroken, and Penny for her part felt guilty for having set him up with a woman she barely knew in the first place. She thus tried to be there for Raj the best she could, and this scene cemented their friendship as Penny became someone Raj could pour his heart out to.
Penny Singing For Sheldon
Any fan of the sitcom would be familiar with 'Soft kitty, warm kitty', the song that went on to be as iconic as the show itself. The first time the song makes it appearance is in the first season--"The Pancake Batter Anomaly"--when Sheldon is sick; he's also been abandoned by his friends, Leonard, Raj, and Howard, who stay away from him purposely so as not to endure him as he becomes growingly unpleasant.
It's Penny who gets the brunt of it all as she gets stuck with Sheldon. The latter makes a tremendous fuss and eventually gets Penny to sing him the song that his mother sang for him as a boy. The moment is funny, of course, but also heartwarming in the way that Penny ends up taking care of Sheldon.
Sheldon Singing For Penny
The exact opposite is also true in how Sheldon takes care of Penny when the latter slips and falls in her bathtub in season 3, episode 8, and has to be driven to the hospital. As literally no one else is available, the task falls on Sheldon and suffice it to say that he actually does help her in his own awkward, self-centered sort of way.
Sheldon starts singing 'Soft kitty' for Penny until the latter, in her drug-addled state, decides to sing along with him. The scene is adorable in how Sheldon lets his guard down and allows himself to come closer to Penny as a friend.
Penny Sitting With Sheldon On His Birthday
If Sheldon was affectionate, however tangentially, towards Penny, the latter too felt protective towards him. As the only person in the gang who didn't have a science background, Penny would often end up being there for Sheldon in the more ordinary day-to-day life. She was the only person that Sheldon was shown opening up to about his habit of knocking thrice on a door, a secret he hadn't even shared with Amy who was in a relationship with him, or Leonard, his best friend.
However, fans would always "The Celebration Experimentation" in season 9 where Penny chose to sit with Sheldon on the ledge of the bathtub at his own birthday party when he felt uncomfortable with the guests, and preferred to hide out in the bathroom. Penny gave him company as he eventually gathered the courage to come out, and the scene is a fan-favorite as it showed the way in which the Sheldon-Penny relationship had evolved, and also portrayed Penny in a mature light.
Raj & Penny Doing Everything Together
From not being able to talk to women without a few drops of alcohol in his tummy, Raj went on to become firm friends with Penny and there was a time when he and Penny would do almost everything together including trying on face masks together. And Raj knew more about Penny's professional life than Leonard ever did.
The scenes in "The Collaboration Fluctuation" show the two to be almost inseparable and Penny is clearly very comfortable with Raj. It is also heartwarming to see the latter, who is perpetually lonely, find such a close friend in Penny.
Sheldon's Saturnalia Miracle
In season 2, episode 11, "The Bath Item Gift Hypothesis", Penny gifts Sheldon a napkin for Christmas that had been used by actor Leonard Nimoy who played Spock, Sheldon's favorite character in the Star Trek franchise. The latter was deeply moved and presented Penny with all the gift items he had purchased for her instead of picking just one. Thinking that even this wasn't enough, he also gave her a hug, one that took Penny by surprise and that Leonard dubbed as a Saturnalia miracle.
Sheldon's social awkwardness made it difficult for him to connect with other people, which is why this moment is etched in fans' minds as the first time that he was shown to demonstrate some genuine gratitude and friendly affection. The scene might have acted as a foundational moment in what was to become a very significant friendship in the series in years to come.
Leonard & Sheldon Hugging
Season 11 of the series ended on a high with Sheldon finally tying the knot with Amy Farrah Fowler. The season finale also brought with it one of the sweetest and most memorable bromantic moments between Leonard and Sheldon.
Right before Sheldon finally took his vows with Amy, Leonard got a tad sentimental at the prospect of his best friend's wedding. He finally ended up hugging Sheldon affectionately, struggling to control his emotions. The scene highlighted the deep bond between the best friends despite the many times Leonard had expressed his frustrations over Sheldon.