5 Worst Penny Moments On The Big Bang Theory, Ranked

To be clear, when it comes to the main characters of "The Big Bang Theory" — the wildly successful and eternally beloved sitcom created by Chuck Lorre and Bill Prady that ran for twelve seasons — Kaley Cuoco's Penny is the best of them. Still, she has her bad moments throughout the series ... and we're going to talk about five of them.

Let's go over Penny's whole deal first, though. After moving to California to pursue a career as an actress, she moves in across the hall from California Institute of Technology physicists Sheldon Cooper and Leonard Hofstadter, played respectively by Jim Parsons and Johnny Galecki. Sheldon is bemused by her, Leonard is besotted, and soon, she meets their friends and colleagues Howard Wolowitz and Raj Koothrappali (Simon Helberg and Kunal Nayyar) and officially becomes part of the friend group. Eventually, the show adds some much-needed feminine energy in the form of Amy Farrah Fowler, played by Mayim Bialik, and Bernadette Rostenkowski, played by Melissa Rauch.

Because Penny is the only non-scientist in this entire group, she often acts as an audience surrogate to help us understand this gaggle of nerds ... and as the only one with any real discernable social skills, she also helps this gang of rag-tag dorks assimilate into the world with a little more ease. Still, she does some stuff that's just not particularly great, so here are the worst things Penny does on "The Big Bang Theory," ranked.

In Season 6 of "The Big Bang Theory," Penny and Leonard are pretty happily dating ... before they "enjoy" one of the worst Valentine's Day dinners in TV history. As Sheldon and Amy, also a couple, go to extreme lengths to find perfect gifts for each other, Leonard and Penny try to make the best out of the romantic holiday, and they agree to a double date with Howard and Bernadette after Howard accidentally breaks the gift he was trying to make by hand for Bernadette.

To say the dinner goes poorly is a pretty big understatement. Bernadette and Howard are mid-fight by the time they even arrive — Bernadette stole and hid Howard's gaming console after he spent too much time playing "Assassin's Creed" and neglected their shared load of laundry — and even though Penny is impressed by the fancy restaurant, her mood sours immediately when she sees her ex-boyfriend dining with his new girlfriend. (As it happens, said ex-boyfriend cheated on Penny ... with this exact new girlfriend.) Leonard hastily tries to propose, which only makes Penny angrier, and she spends the entire evening obsessing over this guy and the fact that he's marrying the girl who broke them up. 

This is understandable, sure, but it's sort of cruddy of Penny to ignore her boyfriend and whine about a guy who screwed her over on Valentine's Day. It's not the worst thing Penny ever did, but it's not great, if we're being honest.

By the time Season 8 of "The Big Bang Theory" rolls around, Penny has changed careers, giving up her dream of becoming an actress to work as a pharmaceutical sales representative (working alongside microbiologist Bernadette, actually). In "The Expedition Approximation," Penny enjoys the literal fruits of her labor by giving Leonard, now her fiancé, an envelope full of cash; as she tells him, she sold the car he bought her years ago after her job offered her a company car. Not only is Leonard hurt that she sold a gift without telling him, but he refuses the money.

Could Penny have handled this better? Probably! When Leonard gets upset that she sold the car only to present him with a cash-filled envelope, she shoots back, "What should I have done? Taken a picture of it and put it in a frame with little hearts and puffy letters that say 'Best Fiancée Ever?'" By the time the episode ends, Penny and Leonard are at peace with the idea that, with her new job, she's probably going to end up making more money than he does ... but her behavior leading up to that point isn't exactly wonderful.

Saying "I love you" in a relationship is hard, and when it comes to Penny and Leonard's relationship, it's always easy to see that Leonard falls head over heels in love long before Penny fully reciprocates that feeling. That's what makes her behavior in the Season 3 episode "The Wheaton Recurrence" so tough. While the couple is in bed together, Penny impulsively quotes Yoda from "Star Wars," and Leonard blurts out that he loves her; Penny thanks him, making them both feel unbelievably uncomfortable. This weirdness between them persists until they join Sheldon in a bowling competition against his nemesis, Wil Wheaton — who basically plays an evil version of himself — and Leonard keeps trtying to have a conversation with Penny about whether or not she loves him.

If we're being completely honest, everyone behaves badly in "The Wheaton Recurrence." Wheaton interferes by telling them a horror story about his own failed relationship, Leonard won't stop pestering Penny, and instead of being completely upfront about the fact that she's afraid to say "I love you" back to Leonard because of past experiences, Penny just keeps fleeing the scene. Amazingly, the only person who acquits himself somewhat admirably is Sheldon, who actually seeks Penny out to see if she's okay. Still, Penny's instinct to run whenever Leonard starts acting up isn't great, but thankfully, she does love Leonard and tells him that eventually.

Not only is the name of the Season 2 episode "The Dead Hooker Juxtaposition" incredibly gross all by itself, Penny's behavior in this particular episode of "The Big Bang Theory" is gross to boot. Why? She wages a war against her, Sheldon, and Leonard's new neighbor Alicia (Valerie Azlynn), but for all the wrong reasons. When the beautiful blonde Alicia moves in, Penny is immediately jealous that another "hot girl" will end up living in the building, and she immediately resents her; meanwhile, Alicia takes full advantage of the fact that Leonard, Raj, and Howard are all incredibly infatuated with her and gets them to do menial tasks around her house for free.

Penny isn't just jealous of the fact that all the guys are into Alicia and now ignoring her — Alicia is also an actress who happens to have found a bit more success than Penny at this point — but the point here is that Penny isn't angry that Alicia is taking obvious advantage of the guys. Penny is angry because she usually takes obvious advantage of the guys, stealing their WiFi and enjoying their takeout just because she's pretty and they want to impress her. Penny ultimately gets into a fistfight with Alicia and gets a black eye and fat lip for her trouble, and she kind of deserves that fate, honestly.

One of the most unpopular storylines in "Big Bang Theory" history begins in the Season 4 finale, when a disheveled Penny leaves Raj's room in a drunken haze so that both the other characters and the audience think the two slept together. This all gets resolved in the Season 5 premiere, the awkwardly titled "The Skank Reflex Analysis," but the resolution isn't great ... and the whole thing makes Penny look pretty profoundly terrible.

At this point in the series, Raj is still suffering from selective mutism due to his overwhelming anxiety around women; after he and Penny drink a bunch of wine together, they wake up in bed — specifically, Leonard's bed, so Penny's ex-boyfriend's bed! — in a state of undress. This happens in the Season 4 finale "The Roommate Transmogrification," and we find out in "The Skank Reflex Analysis" that while Penny and Raj almost slept together, Raj experienced some ... technical difficulties, so nothing actually happened and they simply both passed out. This whole ordeal makes Penny look selfish, callous, and incapable of making a good decision, and though Raj is also at fault somewhat here, it's the worst thing she does on "The Big Bang Theory."

You can watch Penny's highs and lows on "The Big Bang Theory" on HBO Max now.