Every Season Of The Big Bang Theory Ranked Worst To Best
Once upon a time, hitting the ten-season mark wasn't that unusual for a popular sitcom. However, given that the sitcom world isn't what it used to be — a result of the rise of streaming and numerous other factors — it's entirely possible that "The Big Bang Theory" might go down as being one of the last shows of its kind to last for over a decade. What sets "The Big Bang Theory" apart from many other long-running sitcoms is that none of the seasons are universally considered bad: The show started strong, and it was still among the highest-rated shows on television when it ended.
With that in mind, it needs to be made clear that even the worst season of "The Big Bang Theory" is still far from bad. Some seasons are definitely better than others, but, unlike most lists ranking the seasons of a long-running show from worst to best, you'll still find mostly kind words about the lowest-placed seasons. When "The Big Bang Theory" was at its best, it was something special and represented what is so great about sitcoms. So, without further ado, here's every season of "The Big Bang Theory" ranked from worst to best.
12. Season 8
It's more or less expected that a show that is on the air for many years is going to see at least some form of decline as it goes on. Certainly, the lesser seasons of "The Big Bang Theory" came nearer the end. But the show does deserve credit for bouncing back after Season 8, which is the worst season overall for a number of reasons.
As Season 7 wound down, it seemed to be setting things up for a major change. Sheldon was presumably going to be living alone now that Leonard had moved into Penny's apartment as they started down the road to marriage. But it felt like the writers were worried that the show wouldn't work without the dynamic of Sheldon as the live-in third wheel, so everything was basically back to normal a few episodes into Season 8 — which was a huge disappointment.
Highlights of Season 8 include the mock prom, Rajesh's relationship with Emily, and Sheldon and Leonard facing an online bully that was revealed to be Stephen Hawking. And the show was forced to deal with the death of the actor who played Howard's mother (Carol Ann Susi) by also having his mother pass away suddenly, adding an emotional punch. All in all there were plenty of funny and heartfelt episodes in Season 8, but it just felt like a show spinning its wheels a bit at this point.
11. Season 11
One of the biggest downfalls of sitcoms is how they handle relationships. It is much easier to mine comedy out of two people who are still circling each other romantically, and things get a lot more tricky creatively once a relationship is made official. To the credit of the writers, "The Big Bang Theory" handled the unorthodox relationship between Sheldon and Amy very well, making it feel truly earned. It took roughly eight seasons for the couple to finally tie the knot, and their wonderful wedding episode was a definite highlight of Season 11, even as other aspects of the show dragged the season's overall quality down a bit.
Preparing for said wedding took center stage for much of Season 11, and although the end result was expertly handled, it got a little old having the ups and downs of its planning be stretched across almost an entire season. Even something as big as Howard and Bernadette finding out they are having another baby ended up mostly taking a backseat to the wedding, which wasn't fair to those characters. Tellingly, Season 11's best episode that wasn't the wedding itself was a flashback episode about bitcoin mining that very much felt like classic "The Big Bang Theory."
Sheldon making up with his brother George (one of the show's most underrated recurring characters) was also a highlight — even though that episode was still technically wedding-adjacent, since Sheldon was ultimately trying to make nice with George so he'd come to the wedding.
10. Season 9
Season 9 was one of major transitions for the three main couples in "The Big Bang Theory." Leonard and Penny elope in Las Vegas and have to adjust to life as a married couple; Sheldon and Amy recover from their break-up by making love and getting engaged; and Howard and Bernadette find out that they are going to be parents. Raj, the only main cast member to not pair off with another main cast member and who struggled in relationships throughout the series, suddenly finds himself in a love triangle in Season 9.
It seemed like the creative team had a sense that the previous season was on the weaker side — or at least played things too safe — as Season 9 was one of big risks. It also had a slightly more dramatic overall vibe than most seasons, though you could argue that the show was simply maturing rather than trying to be edgier for the sake of it. Sheldon getting dumped by Amy served as a major turning point for the character, giving the show an excuse to have him shed some of the quirks that had grown more tiresome than funny in the previous season or two.
However, while characters like Sheldon and Howard were allowed to evolve in interesting ways in Season 9, Raj unfortunately took a huge step backward. The other big thing that kept Season 9 just good instead of great is Leonard and Penny's arc. Their journey into married life wasn't particularly well explored in its early stages.
9. Season 10
After a couple of rocky seasons for two of the show's main couples, Season 10 saw both Sheldon and Amy and Leonard and Penny take major steps forward. Sheldon and Amy finally move in together, though not without some deception on Amy's part. As for Leonard and Penny, they decide to have an actual wedding ceremony to make their nuptials feel more real and to allow family and friends to share the moment with them. After this, they seem more ready to begin life as husband and wife than they were after their elopement.
As if a wedding wasn't already risking a major shark jump, Season 10 also saw Bernadette finally give birth to her baby with Howard. Though, to the show's credit, none of these things ended up spelling serious creative doom and they actually helped the series rebound after a relatively weak season. Even Raj gets back on track as a likable character this season, with the show no longer trying to portray him as some kind of callous Lothario, which was never a good fit for him. He is also financially cut off from his father, which is a good thing, as Raj's safety net of seemingly unlimited money was wearing thin. This gives him another relatable source of conflict to further re-endear him to the audience.
8. Season 12
For the final season of a sitcom as long-running as "The Big Bang Theory" to not be its worst, and to actually fall somewhere in the middle quality-wise, is a major accomplishment. Season 10 was a great rebound from Season 9, but then things took another dip with Season 11. Thankfully, the show didn't follow this downward trend as it crossed the finish line. While we respect Jim Parsons' decision to quit "The Big Bang Theory" on his own terms, and the show for knowing better than trying to continue without Sheldon, it does leave the question forever unanswered of how many more good seasons it could've had, given that it was bouncing back so nicely here.
With weddings and babies out of the way, Season 12 needed other big arcs to rely on. Raj and his arranged relationship with Anu is a big one, and while it might have been sad to have him be the only unattached main cast member in the finale, Raj deciding not to settle and realize that he deserves someone who's a better fit for him is ultimately a more satisfying wrap-up for the character. Even Stuart, the most downtrodden and eternally unlucky character on a show full of such characters, finds love in Denise, who he's still with in the end — and this feels sufficiently earned rather than forced.
Perhaps fittingly, the big topper on the series isn't romance-based — it's Sheldon and Amy winning the Nobel Prize. Still, perhaps the most satisfying moment in the finale for longtime fans was finally seeing the elevator working.
7. Season 6
From here on out, we are in the seasons that are all considered great. That's not to say that they are all flawless and don't have dud episodes or misguided arcs, but Season 1 through Season 7 definitely represents "The Big Bang Theory" at its best — the good far outweighed the bad during the show's initial stretch. While Leonard and Penny's relationship doesn't take any significant steps forward in Season 6, it is still a fun dynamic to watch at this point in the show. Sheldon's attractive new graduate student assistant Alex, who has a thing for Leonard in a big way, causes Penny to feel something in her relationship with Leonard that she didn't think was possible: jealousy.
Even more fun, though, are Sheldon and Amy, who are still taking their time to figure out this whole romantic relationship thing — this is mostly Sheldon's decision, of course. In Season 6 we see some of the first examples of Amy's patience with the progress of the relationship beginning to wear thin, but it's still mostly just light and funny at this point and hasn't led to any serious drama yet. Season 6 also sees Howard working on the International Space Station, which is a fun gimmick to shake up the status quo a bit. Stuart also has a bigger role than he had previously, finally starting to dip his toe into the friend group rather than just being the guy at the comic book store.
6. Season 1
When looking back at most shows — especially comedies — in retrospect, the first season often feels like the weakest. It's understandable, as the kinks are still being worked out, characters are still finding their voice, ensemble dynamics are still taking shape, and the overall worldbuilding of the show needs to happen. So it's remarkable, then, that Season 1 of "The Big Bang Theory" still holds up as one of the show's best and only just missed out on our top five.
Much of the first few episodes in particular are focused on Leonard and Sheldon meeting Penny, and Penny then slowly finding herself folded into the group with Howard and Raj as well. As far fetched as it might seem that this gorgeous, popular girl would so quickly start hanging out with these awkward — and, in Howard's case in particular, somewhat creepy — nerd dudes so quickly, the way the show is written and the way the actors play the characters makes it feel extremely believable. Sure, there are a few episodes that see characters saying and doing things that don't fit with the way they would eventually be established, but that's par for the course when it comes to debut sitcom seasons.
While the likes of "Seinfeld," "The Office," and "It's Always Sunny in Philadelphia" have first seasons that many fans skip (or at least very quickly buzz through), "The Big Bang Theory" stands apart from these shows as a sitcom with a solid first season.
5. Season 7
Season 7 was the last great season of "The Big Bang Theory" for several key reasons. Basically, every character saw a major step forward in their evolution, either for the better or at least for the more interesting. Raj, now no longer suffering from female presence-induced mutism, has entered the dating world. Amy gets closer to the everyday action as she takes a job at the university. And Penny quits her waitressing job in order to devote herself to pursuing an acting career full-time.
In addition, Season 7 is a great one for both recurring and guest characters. It sees the passing of Bob Newhart's Dr. Proton, though he continues to make appearances as a Force ghost-esque apparition that speaks to Sheldon. The comic book store burns down, which leads into the entertaining arc of Stuart being the live-in nurse of Howard's mother — which would eventually lead into him being a long-term houseguest of Howard and Bernadette. There's some great stuff from Leonard's mom, university HR person Janine Davis, and fellow university employee Barry Kripke, not to mention memorable appearances by Carrie Fisher, James Earl Jones, and Bill Nye. The main cast, the recurring cast, and the guest stars are all firing on all cylinders in Season 7.
4. Season 4
Though much of "The Big Bang Theory" was built around Leonard and Penny, and it was undoubtedly at its best when their relationship was going in interesting directions, there were also some memorable stretches where one or both of them were with someone else. Case in point: Season 4, which heavily features Leonard and his relationship with Raj's sister Priya. They are ultimately not a great fit, as Priya seems to bring out the worst in Leonard and also takes advantage of his meekness in ways that Penny never did. But it's still entertaining to watch, and it proves pivotal to Leonard's character development and his later recoupling with Penny after their brief try-out in Season 3.
Bernadette and Amy, recurring characters in the previous season, are smartly added as series regulars in Season 4. Beyond just setting up eventual love connections for Sheldon and Howard, the addition of these two characters serves to better flesh out the ensemble as a whole — not just in the obvious way of giving it a stronger female voice, but also in adding two genuinely unique and interesting personalities into the mix.
To that end, Season 4 has the excellent episode "The Love Car Displacement," in which everyone convenes at a science conference and sparks fly between multiple members of the group. It can be difficult to properly balance a storyline that involves an entire main cast, but episodes like this proved that "The Big Bang Theory" was capable of doing that extremely well.
3. Season 5
Season 5 of "The Big Bang Theory" would still be great if the only major thing that happened was Leonard and Penny finally deciding to give their relationship a real shot. They might not have consistently stayed together from this season to the finale, but for all intents and purposes, Season 5 is when the Leonard and Penny era officially begins. Another major milestone in Season 5 is Howard and Bernadette's relationship fully taking off, as Howard becomes a much better character once his lecherous ways are mostly put behind him — this was an aspect of his character that was never great to begin with and had overstayed its welcome by this point.
Amy really comes into her own in Season 5 as well. She initially felt a little too much like a female Sheldon, but by this season she had finally evolved into more of her own character. Her budding friendship with Penny and Bernadette not only made her much more than just a romantic partner for Sheldon, it also formed a second, separate female friend group that had its own storylines outside of the guys. Season 5 also marked the start of Raj's relationship with Emily, which would last longer than any relationship Raj has throughout the series. Emily proves to be quite the unique character, becoming a fantastic foil for Raj.
2. Season 2
With all the Season 1 setting up out of the way, Season 2 of "The Big Bang Theory" really came out swinging. Penny briefly dates Stuart; Leonard rekindles his unusual relationship with Leslie Winkle (which reunited Johnny Galecki and Sara Gilbert, previously appeared opposite each other on "Roseanne"); Penny gets addicted to online gaming; Howard invents an ultimately faulty space shuttle toilet; and we see Rock-Paper-Scissors-Lizard-Spock being played for the first time.
There is so much going on that it's hard to narrow down all the hilarious moments or pivotal episodes from Season 2. In retrospect, the absence of Bernadette and Amy is hard to get used to, but recurring/guest characters like Leslie, Dr. Barnett, and Ramona really help to add the necessary female presence to the show. Season 2 also has the notable debut of Beverly Hofstadter as Leonard's cold, matter-of-fact psychologist/neuroscientist mother, who would go on to be such an important character as the show went on.
While "The Big Bang Theory" was a hit with audiences from the beginning, critics weren't impressed with Season 1. However, they were thoroughly charmed by Season 2 — and the season's impressive 100% Rotten Tomatoes rating over Season 1's 59% is proof of that. Ratings for all subsequent seasons of the show remained on the fresh side.
1. Season 3
What makes Season 3 of "The Big Bang Theory" the best of the bunch? Well, let's start with the aforementioned introduction of Amy and Bernadette, who would soon become equals in the overall ensemble. Then there's the fun — but also deliciously awkward — beginnings of Leonard and Penny trying to figure out if they can actually make things work as a couple. This season also boasts the debut of Wil Wheaton (playing a version of himself), who goes back and forth between being a friend and nemesis to Sheldon for basically the entire run of the show. And, speaking of cameos by famous people, Season 3's list is particularly long, including the likes of Stephen Hawking, Stan Lee, James Earl Jones, and Elon Musk.
We haven't mentioned Sheldon's mother yet. Played by Laurie Metcalf (yet another "Roseanne" alum), she shines every moment she's on screen and is one of the best parts of the stellar season premiere. And while flashback episodes are often groan-inducing and the weakest part of a TV comedy, "The Staircase Implementation" is a case study for how to do it right. Leonard tells Penny all about meeting and moving in with Sheldon, as well as meeting Raj and Howard, and also the long-awaited origin of the apartment building's broken elevator.
Season 3 does a great job of both looking back — including to events that predate the show's timeline — and setting up the show's future while also showcasing everything that makes "The Big Bang Theory" such a treat.