Actress Kaley Cuoco has been around the entertainment world since the 1990s, but her rise to fame came with the ABC family series 8 Simple Rules…for Dating My Teenage Daughter. Born in California, Cuoco landed her first acting role when she was ten years old, and she had her first consist appearance on a television series five years later on the CBS sitcom Ladies Man. Two years after that, she landed her defining role on 8 Simple Rules. While many child actors find themselves unable to transition into adult roles, Cuoco has proven herself capable of taking on the challenge.

Ever since her appearances on 8 Simple Rules, she has racked up credits on popular series like The Big Bang Theory, where she played one of the lead characters, the television series Bratz, and, recently, The Flight Attendant. Now in its second season, The Flight Attendant was adapted by Cuoco’s production company Yes, Norman Productions, and the actress stars in the show’s leading role. Cuoco has become an actor instantly recognizable for many viewers across the world, especially as she chooses new roles that further her popularity. That said, these are her best performances so far.

Related: The Big Bang Theory: Where the Cast is Today

6 8 Simple Rules...For Dating My Teenage Daughter

Cast of 8 Simple Rules gathers around kitchen table
Shady Acres Entertainment 

8 Simple Rules ran for a total of three seasons before ABC canceled the show. Originally airing from 2002 to 2005, John Ritter starred in this family drama before his untimely death in the middle of filming the second season. He portrays the patriarch of a family of five, and his teenage daughters are getting ready to go out into the world and do what teenagers do, including dating. This father, however, does not want his daughters to do anything, so he lays down strict rules about what they can and cannot do. Cuoco is the eldest daughter in the family, Bridget, who unfortunately falls heavily into the dumb blonde stereotype.

5 The Wedding Ringer

Men dance at wedding.
Miramax

Back in 2015, comedian and actor Kevin Hart starred with Josh Gad and Kaley Cuoco in The Wedding Ringer, a romantic comedy that also serves as a buddy film. Hart portrays Jimmy Callahan, a business owner specializing in only one thing: best man services. When a lawyer (Gad) becomes engaged to his fiancée (Cuoco), he realizes he needs a Best Man and thus hires Jimmy. The lawyer specifically needs seven groomsmen for his wedding, leading to Jimmy scrambling to find the right group of people to get the job done. Naturally, this leads to a series of comedic disasters. While the movie itself may be lackluster in appearances and plot, it gets the job done with the combined efforts of Gad, Hart, and Cuoco.

4 Charmed

Girls stand around spell book.
Spelling Television

The original Charmed television series, which ran for eight seasons across eight years, was a cult classic and underdog when it first aired. Although it was not from one of the major cable companies, it still became one of the biggest television shows of the late nineties and early 2000s. It was also one of the longest-running shows featuring an all-female lead cast until the release of Desperate Housewives in 2012. Three sisters in San Francisco discover that they are some of the most powerful witches to have ever existed, and they must protect the world from any supernatural danger. Cuoco is in season 8, portraying the character of Billie.

Related: Kaley Cuoco Was 'Devastated' Over Losing Knives Out 2 Role to Kate Hudson

3 Harley Quinn

Poison Ivy and Harley Quinn stand next to each other in Suicide Squad black t-shirts.
Warner Bros. Television Distribution

Cuoco’s own production company helped produce the animated version of Harley Quinn, a continuation of the beloved comic book’s character story. Harley Quinn has just broken up with the Joker after realizing he probably doesn’t love her, and so she decides it is time to prove her worth as a big, bad villain. Poison Ivy makes her grand appearance, shifting this into an animated series with solid slow-burn LGBTQ+ representation. While the show allows Harley Quinn to create her own story — a rarity for female characters throughout the history of modern storytelling — it also boasts an impressive array of voice acting, including Cuoco’s performance as Quinn.

2 The Flight Attendant

Flight attendant looks weary on empty plane.
Yes, Norman Productions

Adapted from a novel, The Flight Attendant is everything you wouldn’t want to know about your local flight attendants. Yet, at the same time, it makes for addictive television. Cassie Bowden (Cuoco) is a flight attendant with an alcohol problem and a lot of extra baggage, but one night, after she sleeps with a passenger, she wakes up to find his dead body right next to her. Unaware of what truly happened, she discards the body only to have the FBI on her trail. Cuoco truly brings to life Cassie as a character, as it is quite believable that this woman does not have her life together.

1 The Big Bang Theory

Girl puts arm on man; he is wearing a grey suit.
Warner Bros. Television

The Big Bang Theory has Cuoco’s most defining role so far: Penny. The television series, which ran for 12 years, was one of the most beloved comedies when it was still airing. Penny is a stark contrast to the other main characters, as outlined by Screen Rant, who are physicists, as she represents the average person. With no background in hard science or math, she aspires to be an actress but instead is a waitress in the meantime. While there was potential for Penny to spiral into a dumb blonde stereotype, Cuoco’s nuance and direction turned the character into a complex individual.