Every Season Of The Big Bang Theory, Ranked

Chuck Lorre's wildly successful sitcom "The Big Bang Theory" ran from 2007 to 2019, making stars out of its core cast and becoming one of the most successful entries into the genre of all time. Across that timespan, it aired 12 seasons and 279 episodes. In case you've been living under a rock or you've never turned on TBS to catch it in synidcation, here's a refresher: the show focuses on a gang of nerdy guys — Sheldon Cooper (Jim Parsons), Leonard Hofstadter (Johnny Galecki), Raj Koothrappali (Kunal Nayyar), and Howard Wolowitz (Simon Helberg) — who all work together as scientists at the California Institute of Technology, and in the show's pilot episode, roommates Sheldon and Leonard are surprised when a gregarious and gorgeous girl named Penny (Kaley Cuoco) moves into the apartment across the hall from theirs. 

Eventually, the cast welcomed Melissa Rauch as Bernadette Rostenkowski (a waitress-turned-microbiologist who marries Howard) and Mayim Bialik as Amy Farrah Fowler (a neuroscientist who romances and weds Sheldon) into their ranks, giving the show a much-needed boost of feminine energy and giving the narrative enough cause to keep going for a whopping 12 seasons.

The show apparently could have continued had Parsons not elected to leave — a decision that brought the entire series to a close — so with that in mind, we've got 12 seasons to rank from worst to best. Obviously, many seasons will fall squarely in the middle here, which makes mathematical sense ... but ultimately, I'm here to pick the winners and losers, so here's every season of "The Big Bang Theory" ranked.

Unfortunately for season 10 of "The Big Bang Theory," it's definitely the worst of the worst. To start, Amy and Sheldon's relationship is plagued with problems throughout the series — Sheldon's apparent disgust when it comes to intimacy means that he's usually just mean and insulting to Amy when she tries to initiate any, and frankly, he's just mean to her a lot of the time for no real reason — but this season is absolutely their lowest point. In the episode "The Cohabitation Experimentation," Amy needs to stay with Sheldon after there's a leak in her apartment, and to say it's a disaster is an understatement; despite that, this dysfunctional couple ends up giving relationship advice to Leonard and Penny in "The Romance Recalibration," which is one of the show's worst-ever episodes. (Somehow, these two crazy kids still get engaged at the end of the season, so go figure.)

Elsewhere, Bernadette is stuck with a pregnancy plotline that hits all the standard sitcom notes (she's hungry, cranky, and so on), Penny attends a convention only for fans to be extraordinarily weird to her about her nude scene in a terrible movie called "Serial Ape-ist 2," and Raj has a really offensive plot where he dates his office's cleaning lady but is too ashamed to be around her in public (thankfully, it only lasts for one episode). Season 10 of "The Big Bang Theory" is seriously treading water, and it shows.

Season 9 has the terrible fortune of kicking off with another unloved episode of the show, "The Matrimonial Momentum," where Penny and Leonard rush to elope in Las Vegas (right after Leonard tells her that he kissed someone else during their relationship). From Penny's lackluster vows — she simply says the lyrics to "You've Got a Friend in Me" from "Toy Story" out loud — to the fact that none of their friends are even there, the wedding absolutely sucks. (They have a real wedding in the season 10 premiere, but we've been over that season already.) So what happens otherwise that drags this season so far down in the ranking?

Sheldon and Amy are going through a breakup throughout a lot of season 9, which makes Sheldon — a difficult character at his best — even more irritating, we see the creepiest possible side of comic book store owner Stuart Bloom (Kevin Sussman) when he starts watching Howard and Bernadette sleep, Raj is dating two women and being awful about it, and there's a cameo from Elon Musk (this was a very different time, obviously). Still, it's a rough go, so it falls just above the worst spot.

A season that starts with an episode called "The Skank Reflex Analysis" isn't a good sign, and things don't really improve from there. We'll circle back to the season 4 finale later, but suffice to say that Raj and Penny end up in what appears to be a compromising position; season 5 easily could have just hand-waved that entire thing away by saying the two just fell asleep in the same bed. Instead, we have to sit through a lengthy explanation about how they tried to hook up but Raj got too "excited," which is exactly as interminable as it sounds.

What else? Season 5 of "The Big Bang Theory" prominently features Raj's sister Priya (Aarti Mann), and it's not Priya's fault that she's nothing more than a plot device to keep Penny and Leonard apart, but facts are facts. Howard learns that he's heading to space, starting a very weird subplot that ultimately separates him from the rest of the cast, and Sheldon is mean to Amy several times over. The two saving graces here center on two of the show's central couples; Leonard and Penny eventually do get back together, and Howard and Bernadette's wedding in the season finale is genuinely very sweet.

Much like season 5, season 11 of "The Big Bang Theory" culminates in a wedding, and it's actually very sweet — so let's talk about the season finale, "The Bow Tie Asymmetry," which sees Amy and Sheldon get married in a ceremony officiated by Mark freakin' Hamill. (Even for "The Big Bang Theory," which featured everyone from Bob Newhart to Stephen Hawking, this is a really good cameo.) Otherwise, the season feels like it's placing the chess pieces on the board before the game begins, which makes sense when considering that it's the penultimate installment.

Other than Amy and Sheldon's wedding, Bernadette is now pregnant with her second child, giving her more maternal storylines — and while that's definitely not a bad thing by definition, it does somewhat limit her character development to stick her on such a specific path. Both Amy and Sheldon are sort of frustrating in season 11; in the episode "The Matrimonial Metric," they test their friends to choose a best man and maid of honor, which is objectively pretty mean. Howard and Raj spend a decent chunk of the season fighting to boot, dividing the two friends. Season 11 is okay, but it's not great.

Season 8 of "The Big Bang Theory" doesn't get off to an auspicious start, largely because it picks up where the season 7 finale left off — with Sheldon stranded in Arizona after he fled his own home after being bombarded with too much change. I certainly wish they could have just added a joke about how Sheldon left and came back in the premiere and skipped the premiere "The Locomotion Interruption," but I will give it credit and say the episode does feature a huge leap for Penny: with Bernadette's help, she becomes a pharmaceutical sales representative (and turns out to be pretty good at it, point in fact).

Elsewhere in season 8, we've got some solid episodes like "The Focus Attenuation" — where Penny, Bernadette, and Amy take a delightful road trip to Las Vegas together — and "The Prom Equivalency," where the gang plans a re-do prom on their roof, but a lot of the proceedings are dragged down by Raj's girlfriend Emily (who's not all that nice to him half the time). It does end on a surprisingly emotional note, though; when Amy asks to take a break from her relationship with Sheldon, it's revealed that he bought an engagement ring for her, which is both a gut punch and a pretty solid final moment for the season.

It is a somewhat universally acknowledged truth that comedies don't always find their stride in their first seasons — and aside from the (thankfully) unaired pilot with a different female lead, I will say that "The Big Bang Theory" has a pretty solid start! This is due in large part to the fact that Sheldon, Leonard, Howard, and Raj are all pretty well-defined characters from the jump — Sheldon, in particular, feels so lived-in thanks to Parsons' performance — although the same can't be said for Penny, who gets a rough deal in the pilot and is stuck playing a basic and bubbly blonde for a little bit. I said for a little bit, though; within the first season, we really get to see Penny shine as a foil for Leonard (who's in love with her) and Sheldon (who thinks she's an idiot).

With that said, Raj's selective mutism is the weirdest trait that the show's writers ever came up with, and it's on full display in season 1 — plus, Howard is a big old creep. Add in the fact that Bernadette and Amy aren't on the show yet and you've got a season that's clearly good — obviously, it captured audiences pretty quickly — but not great.

Season 6 of "The Big Bang Theory" is ... pretty solid, all things considered. Yes, we have to wrap up Howard's whole space plotline, but he's back in Pasadena by the fourth episode (and, after he does return, he experiences a crisis of confidence that's very sweetly handled by his new wife Bernadette). You've also got standout episodes like "The 43 Peculiarity," where Howard and Raj spend an entire workday trying to figure out weird Sheldon behavior (and the solution is genuinely funny), and "The Bakersfield Expedition," where the girls try to understand why the guys love comics and the guys get stranded in "Star Trek" costumes on the way to the Bakersfield Comic-Con. Plus, there's the surprisingly emotional episode "The Closet Reconfiguration," where the gang bands together with Howard after he finds a letter from his absent father.

There are also some low points, naturally. "The Tangible Proof Affection" features one of Leonard and Penny's worst botched proposals, and in "The Extract Obliteration," Penny enrolls in community college and is excited about an assignment until Leonard does it for her because he's worried she's not smart enough. Come to think of it, a lot of this season's shortcomings are related to Leonard and Penny. At least these crazy kids get it together eventually.

Season 4 of "The Big Bang Theory" is actually pretty good, but it loses a lot of ground over its absolutely bizarre season finale. We already went over this — and unfortunately, the season 5 premiere continues the storyline about Penny and Raj's ill-advised night together — but as for the rest of the season, it does a good job bringing Bernadette and Amy fully into the fold and expanding the universe as a result. (Penny is also absent from two episodes in this season because Kaley Cuoco actually experienced a serious real-life injury.) Sure, the season does open with a plotline about Howard building a robot hand with whom he can spend his lonely nights, but thankfully, that feels like a bug here rather than a feature.

Frankly, there are just a lot of good "Big Bang Theory" episodes in season 4. "The 21-Second Excitation" has a great showdown between the guys and Sheldon's erstwhile nemesis Wil Wheaton (playing himself), and the following episode, "The Boyfriend Complexity," has Penny pretending that she and Leonard are still dating to impress her stern father. "The Love Car Displacement" puts all of the gang's quirks on full display, "The Agreement Dissection" features a very funny night out with the girls and Sheldon, and in "The Herb Garden Germination," Bernadette and Howard get engaged. Yes, the season finale is rough. That's okay, though.

A major reason that season 2 of "The Big Bang Theory" doesn't crack the top five is pretty simple: Amy and Bernadette aren't on the show yet, and they really do make it that much better. Still, this is a very enjoyable outing for the show; after a few growing pains in season 1, the show finds its footing firmly in its second outing and gives the characters more room to grow and play.

Unfortunately, Penny and Leonard's attempt to date goes badly, so Leonard ends up involved with both Leslie Winkle (Sara Gilbert) and Dr. Stephanie Barnett (Sara Rue), the latter of whom quietly moves into Leonard's apartment (he doesn't notice until his friends point it out), and after she's confronted, she disappears from the show entirely. Still, Penny has plenty of fun and feels out her friendship with the guys, and in one of the season's very best outings, "The Barbarian Sublimation," Penny gets addicted to the video game "The Age of Conan" and more or less goes insane. She also forces Raj to actually speak an apology out loud to her after he tells his parents that she's his girlfriend, finally getting him to talk in front of her. There are some other low points — "The Panty Piñata Polarization" is one of the show's creepiest episodes, which is saying something — but not only does this season introduce important characters like Ramona Nowitzki (Riki Lindhome) and Barry Kripke (John Ross Bowie), it also builds out the universe really well.

Yes, season 12 of "The Big Bang Theory" involves some significant wish fulfillment, but give the show a break! It's the final season, and it's nice to see (almost) everybody get a happy ending! Newlyweds Amy and Sheldon figure out how to navigate their marriage, the lonely Stuart finally finds love with his colleague Denise (Lauren Lapkus), Penny and Leonard are finally pretty stable in their relationship, Howard and Bernadette are busy raising two kids, and Raj almost enters into an arranged marriage with a girl he actually ends up liking, Anu (Rati Gupta).

Season 12 is likely most fondly remembered for its finale "The Stockholm Syndrome," though, which is fair. Amy and Sheldon win the Nobel Prize for their shared work in super asymmetry, Leonard and Penny find out they're expecting a baby, and Sheldon finally decides to get his head out of his own butt and be nice to his friends. It's a sweet ending! The rest of the season spins its wheels a tiny bit, but it does stick the landing.

Season 3 of "The Big Bang Theory" lands at second place on this list because while it's really good, it's not perfect. It gets off to a strong start in the premiere, when, after Sheldon, Leonard, Howard, and Raj return from an expedition at the North Pole, Penny immediately makes her feelings for Leonard quite clear by kissing him; the two end up feeling awkward after they finally hook up, leading to a very funny sequence in the second episode, "The Jiminy Conjecture," where they get drunk to deal with the weirdness and just end up puking together. (Good way to bond, I guess!) The two do end up dating in earnest, but in the surprisingly emotional episode "The Wheaton Recurrence," Leonard pushes Penny to get too serious too fast, and the fact that she ends things is actually understandable.

Beyond that, Howard meets his match in Bernadette, and though Amy is introduced in this season, it's not until the very end ... so we don't get a full dose of these two extremely important characters in the third season. Still, with episodes like "The Staircase Implementation" (where we learn about the beginning of Sheldon and Leonard's friendship) and "The Precious Fragmentation" (where the boys all fight over a replica of the One Ring from "Lord of the Rings"), season 3 is almost the show's best one.

The bottom line is that season 7 of "The Big Bang Theory" is the show firing on all cylinders. The cast has now expanded to include Amy and Bernadette fully, and with Howard and Bernadette married, he's a much easier character to deal with on basically every level; this might also be the sweetest season. "The Romance Resonance" has one of Howard and Bernadette's best moments of all time — where he sings her an original love song for the anniversary of their first date while she's quarantined due to an accident at work — and "The Cooper Extraction" is a weird one, but explains why these specific couples all end up together utilizing a "Sliding Doors"-style narrative where Stuart imagines what would happen if everything was different. "The Locomotive Manipulation" might show Sheldon at his worst, but it's also a great outing for the whole group.

Ultimately, "The Gorilla Dissolution" is one of the show's very best episodes, ending with Penny and Leonard finally getting engaged and helping Penny realize what's most important to her; not her acting career, but her relationship with Leonard. This ranking was tough, but season 7 of "The Big Bang Theory" is the show at its best, and you can stream it on Max now.