As an ensemble cast, The Big Bang Theory has amazing chemistry as a whole, and that's largely in part due to the actors getting along beautifully off-set too, according to Metro. Fans loved the friendships among the group — even between Sheldon and Howard who didn't always see eye-to-eye.
And while the couples on the show had great chemistry, there are other pairings who also had a great connection on screen. From friends to short-time lovers, there are a handful of characters who radiated good vibes in most scenes. These pairings weren't always shown as much as viewers would have liked but their spark is remembered now that the series has ended.
Penny & Sheldon
Penny and Sheldon went from complete strangers who lived across the hall from each other to best friends who valued each other's opinions. Fans loved how affectionate Penny was with Sheldon.
Their moments together were some of the best because they were so different yet wanted to learn from each other. Whether it's a maternal bond or a sibling-like one, their connection was felt off-screen. Their genuine adoration and protection for each other felt deep.
Leonard & Sheldon
Sure, best friends have natural chemistry, but there was something special about Leonard and Sheldon's friendship. Some of the best standalone episodes revolved around their bond and how they met in the first place. As hard of a person as Sheldon was to love, Leonard did a great job of balancing his ups and downs with him.
As much as Leonard didn't want to live with Sheldon anymore and was bothered by his childlike behavior, he stuck around because of the chemistry they had. No one understood each other quite like the other.
Howard & Raj
There were plenty of fans who felt bad for Raj throughout TBBT because he was the one character who didn't get the happily ever after he was looking for. However, there was one person he could always rely on: Howard.
Howard and Raj were so close that most strangers mistook them for a couple. And while they never were romantically involved, their chemistry was off the charts. It's no wonder people thought they were a couple from time to time by the amount of time they spent together.
Penny & Amy
It wasn't really a kept secret that Amy loved Penny in a multitude of ways. She didn't just want to be with Penny all the time, but she wanted to be just like her in a lot of ways. Amy adored Penny so much that she hired someone to do an oil painting of the two of them.
It took some time for their bond to grow but when it did, their chemistry was magnetic. Just like Penny and Sheldon, as different as she and Amy were, their differences brought them together and made them stronger friends on screen.
Leonard & Stefanie
Dr. Stephanie Barnett and Leonard could have been a match made in heaven. The only problem was that Penny was always going to be in the back of Leonard's mind and Stephanie took things too fast when she met Leonard.
Despite their opposing romantic timelines, these two were a good match for a short time. They had a lot in common and Stephanie didn't mind Sheldon's quirks. In a lot of ways, fans think that Stephanie left the series too soon.
Leonard & Alice
It wasn't just Sheldon and Stephanie that Leonard had chemistry with, he also had extraordinary chemistry with a woman named Alice. The two met at the comic book store and immediately hit it off.
The only problem is that Leonard was in a long-distance relationship with Priya. However, his chemistry with Alice was so strong that he followed his feelings and kissed her. The fallout scene was hard to watch twice, especially since Alice found out that Leonard had a girlfriend, but their connection was strong.
Penny & David
In season 2, Penny met David Dunderhill, a visiting physicist working at Caltech. He and Leonard were teaming up for a project, which is how the two met.
David wasn't a full-time employee at Caltech but he was one of the best-dressed and most attractive. Leonard wasn't prepared for David and Penny to form such a strong connection when they met but their chemistry was off the scales.
Leonard & Penny (Seasons 1-5)
The relationship timeline of Penny and Leonard is a wild ride. From neighbors to friends to lovers to exes — these two have been through it all. The pair eventually left their childish behavior behind and focused on their love for each other and got married in season 9.
However, their chemistry disappeared after they wed. It was when they were on-and-off and flirtatious that their chemistry was most noticeable.
Raj & Claire
One of the saddest parts of Raj's story is that he never found a woman to make his wife. It was a dream of his for so long but it never happened. Fans thought he had a chance at love when he met Claire at the comic book store but it was, yet again, another flop.
And while the two didn't work out romantically, it was one of the more honest moments fans saw Raj with a woman. He was original and unapologetically himself, which was refreshing. Claire appreciated Raj's honesty and a new romance began to blossom. However, their chemistry couldn't keep them together and they called it quits.
Bernadette & Raj
Bernadette and Raj were never in a romantic relationship, but their friendship was, at times, stronger than his relationship with Howard. Bernadette respected Raj and listened to him when he needed an open ear.
Likewise, Raj always had a crush on Bernadette but never acted on it due to his best friend dating her. Nevertheless, when Raj was helping Bernadette with the housework or eating dinner at her apartment, the two had strong chemistry.