The Big Bang Theory: Leonard’s 5 Best (& 5 Worst) Story Arcs
From his relationship with Penny to his friendship with Sheldon, Leonard Hofstadter has had some good arcs. However, there were a few low points too.

The Big Bang Theory caught the attention of millions of people across the world over its 12 seasons, a fresh take on the sitcom genre which followed a group of scientists, and an engineer, comic book nerds, and all-around geeks after meeting the aspiring actress, and charming Penny, who just moved in next door. Among those geeks is Leonard, an experimental physicist, who unlike the rest of the guys, actually has a surprisingly successful time when it comes to dating.
Leonard Hofstadter is one of the original members of the group, who actually appeared in every single episode of the show. He’s a brilliant physicist and like all great tv characters has some great moments throughout the show. However, there is the odd occasion where fans have believed the show would have been better off without a few of them.
Worst: Dating Priya
In what has to be one of the worst relationships in the entire show, and another attempt for the writers to drag out his “will-they-won’t-they-relationship” with Penny, Leonard dated Raj’s sister Priya. Not only did Leonard date her without even talking or mentioning it to Raj, but he even broke his pact with Howard, who both agreed to never date her.
In fact, Priya never even did anything good for the show, instead she just continuously got in the way of Leonard’s friends and his true love Penny. What was worse was that their relationship ended after she cheated on him with her ex-boyfriend. So, was it worth him breaking the bro-code? Definitely not.
Best: Scientific Research
Although Sheldon might be the smartest physicist in the show, Leonard is also unbelievably intelligent. After completing his Ph.D. by the age of 24, Leonard went on to be an experimental physicist at Caltech. The show, unfortunately, doesn’t show much of his work and research, but what it does show is quite remarkable.
In season 8, Leonard and Sheldon publish a paper to do with the superfluid vacuum theory. In earlier seasons, Leonard also showed off his cool work with lasers and had been invited to the North Sea to investigate hydrodynamic simulations of black holes as part of a Hawking Expedition. To earn such an honor means that he had to be one of the smartest people ever.
Worst: Cheating On Penny
As many fans remember, while he was traveling along the North Sea, Leonard cheated on Penny with his co-worker, Mandy Chow. While people do make mistakes, fans will agree that Leonard should have come clean and apologized to Penny as soon as he got back home in season 7.
Instead, he kept it a secret. If that wasn’t bad enough, he decides to clear his conscience by telling her on their wedding night that he cheated all those months ago. It was an incredibly stupid decision from the scientist, and a mistake no one should ever make.
Best: Resolving His Relationship With His Mother
One of the most troubled and complicated relationships of the entire show is Leonard’s relationship with his mother. Beverly Hofstadter was first introduced to fans in season 2, and straight away, fans noticed her detached relationship with her son. In fact, as she keeps returning throughout the show, the viewers find out how many ordeals Leonard was put through, and that he wasn’t much more than an experiment to her.
From not celebrating his birthdays to acting warm and nice just for her new book, it seemed their relationship could never be fixed. But in the final season, Leonard finally confronts her about it. In a heartwarming emotional conversation, the two overcome their problems and hug it out. A beautiful ending to their complicated relationship.
Worst: Making Fun of Zack
Before Penny and Leonard got serious, both of them dated plenty of other people. One character that fans wanted to see more of, however, was charming, handsome, and kind-hearted Zack.
As fans remember, the initial meeting between Zack and Leonard didn’t go very well after the guys continuously making fun of Zack and his low intelligence. This was a particular side of Leonard the fans didn’t like as they felt that it was unwarranted and unnecessary. Thankfully, Penny told them off for being bullies but it still didn’t erase that annoying part of Leonard’s personality.
Best: Hanging Out With The Guys
Whilst the show does eventually focus more on the relationships between the couples, initially, The Big Bang Theory was all about the four scientists and geeks hanging out. They played fantasy board games like Dungeons & Dragons, battled it out with their videogames, participated in Raj’s weird but wonderful scavenger hunts, and dressed up to go to Comic-Con every year.
Even though these little moments occurred less and less as they all settled down and matured, they were still an integral part of the show and led to some of the funniest moments. The show was based around nerdy scientists, and that’s exactly why fans loved these moments.
Worst: Talking Down To Penny
Penny and Leonard’s relationship was one of the building blocks of the entire show, and they were obviously a great couple and perfect for each other. However, there were moments where Leonard stepped over the line. One particular incident was when Leonard tried to get Penny to go to community college without realizing this would make her feel like she was significantly less smart than him and his friends.
He also resorted to hiding and saving money without telling her, which, even though she was not the most reliable with money, should never have been kept secret from her. Not to forget how he repeatedly talked down to her about her career choices. He could be awful sometimes.
Best: Sheldon’s Friendship
When fans were first introduced to the show, the main characters were quite clearly Leonard, Sheldon, and Penny. It didn’t take long for them to realize that Sheldon and Leonard had a somewhat complicated but special relationship. Both are physicists with very high IQ’s but seem to have some quite drastic personality differences.
While they did have several small fights and petty arguments, it was clear that they understood and deeply cared about one another. Despite Sheldon’s over-controlling roommate agreements and Leonard’s constant irritation at Sheldon’s behavior, they are truly best friends and one of the best parts of the show.
Worst: Penny’s Pregnancy
After finally getting back together after many ups-and-downs, Penny and Leonard seemed to have a comfortable life together. They were in love. However, this didn’t stop them from arguing about their futures. Penny was firmly against having kids for years. She didn’t want a family. She didn’t want to get pregnant.
And then, in the season 12 finale, she was pregnant. Many fans would welcome the news, but seeing as she never really wanted children and it was Leonard who kept pressuring her, there was something about this storyline that didn’t quite feel right.
Best: Penny
In the very first episode of The Big Bang Theory, when Penny moved into her apartment next door, it was obvious for fans that it was love at first sight for Leonard. Whilst this crush may have been based entirely on looks, the two formed a beautiful friendship across the next few seasons, proving their connection was more than just physical.
On paper, this relationship shouldn’t have worked. However, Penny and Leonard managed to defeat all the doubters and prove it was true love after all.