Two years after The Big Bang Theory ended, fans of the universe still have plenty of content to consume. The spinoff, Young Sheldon, is doing well and there is even more reason to be excited after actress Kaley Cuoco recently revealed that a book detailing all the behind-the-scenes information will be coming out in October.

Kaley had a great run as Penny but where does her character rank among the rest? Numerous hilarious individuals walked in and out of the sitcom during its 12 seasons, making it tougher to single out those that were better. Luckily, a fan-voted list on Ranker makes it easier to identify the true fan favorites.

Mrs. Wolowitz

Mrs. Wolowitz speaks to Howard in The Big Bang Theory

Deborah "Debbie" Melvina Wolowitz's (aka Mrs. Wolowtiz) face is never shown to viewers throughout the sitcom's run. Instead, she always speaks from a different room.

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The mystery surrounding Mrs. Wolowitz's appearance is what fascinates fans about her. There have been several hints about what she looks like but the show always leaves everyone guessing. Her tendency to scream and bark orders from far away paints her as an overbearing but mirthful parent. While Howard doesn't like it, their awkward exchanges normally result in extremely comical moments.

Bernadette Rostenkowski

An image of Bernadette Looking at Howard in The Big Bang Theory

Bernadette acquires a Ph.D. in microbiology before securing a job at the pharmaceutical company ZanGen. She later gets married to Howard.

Among Bernadette's golden traits are her intelligence and conscientiousness. It's thus fair that she is one of the best paid Big Bang Theory characters, described as earning "a Boatload of money." Conversely, she can be selfish, underhanded, and pushy to both Howard and her friends. This isn't necessarily a bad thing within the context of the show since the conflict she creates normally spices up the proceedings.

Stuart Bloom

Stuart almost gets kicked out of the apartment in The Big Bang Theory

The Comic Center of Pasadena owner is known to have a vast collection of comics and is great friends with most of the main characters. He is also very talented at drawing.

Stuart's kind-heartedness and helpfulness easily place him among the most likable secondary characters in The Big Bang Theory. And even though he often feels sorry for himself for being an underachiever, his confidence has never been affected. As such, he has been a source of competition to Howard and Sheldon by dating Amy and Penny, leading to some interesting relationship arcs.

Mary Cooper

Mary Cooper talking on the phone in The Big Bang Theory

Sheldon's mother appears infrequently throughout the show. She hates his arrogance, which is why she never hesitates to give him a dressing down.

Mary's appearance always triggers plenty of excitement because there is always the guarantee that Sheldon will be put in his place; Leonard has even described her accurately as "Sheldon's Kryptonite." And when she is not telling her son to behave, Mary comes off as wise, kind, and loving. Her love for religion always counters the show's excessive science-related themes too.

Amy Farrah Fowler

Amy Farrah Fowler in her pajamas with a laptop on her lap in The Big Bang Theory

The Havard alumnus, Amy, has a doctorate degree in Neurobiology. She is introduced on the show when she gets discovered by Raj on a dating service as an ideal romantic partner for Sheldon.

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Viewers can always count on Amy to be blunt, leading to some awkward scenarios. Though she is as narcissistic as Sheldon, she has way more positive traits than him, hence she is always the voice of reason in the relationship. Her endearing and close friendship with Penny has also had quite an impact on the fans too since the two women have shown a fierce loyalty to one another.

Leonard Hofstadter

Leonard Hoftstadter flirts with Penny in The Big Bang Theory

The Caltech experimental physicist is a genius, having been awarded his doctorate at the young age of 24. Through Leonard, the struggle of socially awkward people seeking to be more outgoing is often underscored.

Thanks to his desire to step out of his comfort zone, he gets to date Penny, leading to one of the best relationships in The Big Bang Theory. Additionally, Leonard knows how to handle conflict better than most characters, something that's always evident during his arguments with Sheldon.

Raj Koothrappali

Raj smiling in the living room on The Big Bang Theory

The astrophysicist has his own apartment but enjoys hanging out with Sheldon, Leonard, and Howard. Although he was initially seen to be a shy and reserved person, who was afraid to talk to women, Raj ends up undergoing a huge character arc that sees him grow more confident and outgoing.

His friendship with Howard also stands out as fans thoroughly enjoyed seeing the schemes the two got up to on their nights out and how they always help each other in their darkest moments. It's just a shame that his kind-hearted nature wasn't reciprocated by his friends.

Penny

Penny opening the door in The Big Bang Theory

Penny has always had dreams of becoming an actress but she's been forced to take up other jobs to make a living. And unlike the other main characters, she isn't portrayed as well-educated and nerdy.

Characterized as a naive person, Penny is the exact opposite of the other fan favorites. She appeals to viewers by fully embracing her flaws and believing she is the most sensible one of the gang, even though she is not. Still, Penny is ever confident and content too, always trying her best to support her friends in their adventures and even contributing to some of their experiments too.

Howard Wolowitz

Simon Helberg as Howard on The Big Bang Theory

Howard was another character who ended up undergoing a major transformation on the show, starting out as a bit of a bachelor before transforming into a loving husband and family man.

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Many things make Howard stand out. For one, he can be quite witty when he wants to be, always jumping into conversations with a quick jibe that guarantees a laugh or two. He can also be quite stoic as well, never feeling offended even when shady burns are thrown his way. He never gives up either, no matter how many times he fails.

Sheldon Cooper

Sheldon with a toy in The Big Bang Theory

Sheldon prides himself in the fact that he was a child prodigy, having earned his doctorate at the age of 16. He is known to strictly adhere to routines.

As the smartest character on the show, Sheldon never has a problem extracting humor out of his science. He is normally unaware of his numerous annoying traits, something that frustrates his friends but makes him a fascinating character to follow. While he is a meticulous perfectionist, on one hand, he is emotionally immature on the other.

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