Every Season Of It's Always Sunny In Philadelphia, Ranked Worst To Best

As the longest-running live-action American sitcom, with 15 seasons filmed and another four ordered at the time of writing, "It's Always Sunny in Philadelphia" has seen its share of ups and downs. While every season has at least one stand-out episode, the show tends to go in waves: It takes some big swings, finds a sweet spot, and then struggles somewhat before hitting another crest.

Part of what makes the series so satisfying is that, unlike the long-running comedies that begin relying on familiar jokes that grew stale years ago, the "Always Sunny" crew continues to challenge themselves and grow. While not every idea hits, it's impressive that the show continually works to sharpen its satirical voice and expand from its shock-comedy roots. With so much more on the way, now's a great time to look back at the peaks and valleys so far (just for the sake of simplicity, we'll limit our discussion to the episodes currently available on streaming).

Season 11 was the first one to air after the series was supposed to wrap up with season 10, and it can't escape the downright palpable sense of terrified awkwardness that suffuses the text. It's also home to the show's single worst episode, "Being Frank." "Always Sunny" has always struggled with Frank's role; his unnamed wealth opens up opportunities to get weird and his chaotic energy is a vital part of the ensemble's dynamic, but, because he's just a walking ball of (usually gross and bigoted) impulses, the writing tends to suffer when he becomes an episode's emotional lynchpin. It works in "Frank Falls Out a Window," which is a speedrun of season 2 with an added 10 years of technical experience, but "Being Frank" literally shackles the viewer to Frank's perspective. It's not only metaphorically but literally painful to watch, thanks to the shaky camera and filters representing Frank's altered states.

Even in a season that's off its game, though, there are high points. "The Gang Hits the Slopes" gives Glenn Howerton a chance to shine as a comically evil '80s villain. "Mac & Dennis Move to the Suburbs" is a great two-hander, even if it unravels itself slightly too quickly. The greatest joy of season 11, though, is a reward for viewers who've kept track of every running background thread. "McPoyle vs. Ponderosa: The Trial of the Century" unashamedly indulges in the show's longevity and makes the best of it, while also delivering the very important statutes of Bird Law. It's also completely impenetrable to casual fans.

Season 10 feels like another end of a cycle. To say it's "grasping at straws" would be an insult to the level of craft at work, but if the show isn't outright hitting a wall, it feels like one might be around the next corner. Episodes dip into comfortable formulas and end up just shy of the mark. The upsetting-a-rational-human episode "The Gang Goes on Family Fight" is an agonizing exercise in secondhand embarrassment despite the very game contributions of Keegan-Michael Key, while "Psycho Pete Returns" fails to recapture the heights of "The Gang Gets Analyzed." There are still highlights, like the bottle episode "The Gang Beats Boggs," but there's only one episode this season that's a must-watch.

"Charlie Work" is rightly considered one of the best, maybe even the very best, episodes of "It's Always Sunny in Philadelphia." Not only is it a great character-focused episode that shows why Charlie is the glue holding the gang together, but it's also a great showcase of Charlie Day's appealing physicality and a technical marvel that mimics a single tracking shot (before you ask, the crew wrote and shot the episode before "Birdman" came out). An entire season's worth of magnetic energy pours out from those 22 minutes, and it's a terrible shame that, as part of an ongoing series of snubs, this episode received zero awards recognition.

One of the most notable things about "It's Always Sunny in Philadelphia" is how the balance between comparatively grounded episodes, like those that make up season 1, and the more cartoonish and experimental outings of later seasons shift over time. Season 3 can be considered the last transitory step towards a solid sense of what the show really is, weaving in some of the last missing elements and taking big swings to calibrate the overall tone. Episodes like "Frank Sets Sweet Dee on Fire" fine-tune the reliable punchline of cutting from a line of dialogue to a completely contradictory title card; "The Aluminum Monster vs. Fatty Magoo" takes one of the first looks back at the gang's high school days; and "The Gang Dances Their Asses Off" is a prime example of how the writers sometimes inexplicably model an episode on an older, obscure film (in this case, "They Shoot Horses, Don't They?").

On the flip side, "The Gang Gets Invincible" is too focused on repeatedly name-dropping the film it's patterned after. It's not meta as much as it's awkward, especially given that "Invincible" retains absolutely no place in the public consciousness — something the writers themselves acknowledge. The show still has a shaky relationship with slurs, too, particularly those referring to intellectual disability; while the cast is made up of horrible people, the legacy of series like "South Park" show that it's quite easy for the audience to wholeheartedly replicate characters' abhorrent behavior under the paper-thin guise of "irony." And because "Always Sunny" does understand this danger, it leaves some extra cringe on titles like "Sweet Dee's Dating a [Redacted] Person."

Season 7 is a tipping point for viewers, ushering in the more high-concept and exaggerated episodes that characterize several subsequent seasons. It also contains another episode commonly pegged as the show's worst, even though it features an inspired performance by the late Lance Reddick. For those who prefer storylines with at least one foot in the real world, episodes with a Blaxploitation parody and the gang ruining a children's beauty pageant might be less appealing. And yet, the escalating ridiculousness yields scenes par excellence, including a trip to the Jersey Shore that ends with Dee and Dennis having to dig their own graves, a real-time race across Philadelphia to make it to a movie theater, or the latter-day successor to Calvinball, "Chardee MacDennis."

The season's two-part finale, "The High School Reunion," is not just a graceful incorporation of established backstory that still remains accessible to less experienced viewers. In addition, its big dance sequence executes a predictable but hysterical joke while serving as an impressive technical achievement on the part of the cast. It would be inaccurate to call it all a summit, since there isn't a single season without several excellent episodes, but it's definitely a moment of punctuation.

If we were working purely from the showrunners' thoughts, season 5 would be crowned the best. It definitely contains one of the show's most memorable episodes: "The D.E.N.N.I.S. System," which pushed Dennis from someone with garden-variety vanity into a Patrick Bateman-esque malignant narcissist. "Paddy's Pub: Home of the Original Kitten Mittens" also deserves a shoutout for delivering a twist on the show's established formula of setting the Gang loose on a normal person in order to torment them; while it's a trope that's continued to serve "Always Sunny" well, having the Lawyer appear in several episodes as a beleaguered bystander only to pull a much more successful scam on the main cast shakes up expectations and capitalizes on the continuity bestowed to even very minor characters.

What holds season 5 back in a meta-analysis like this is the way its misadventures shake out. This run of episodes builds on the seeds of season 4, cementing "Always Sunny" as a show about a bunch of scheming, horrible losers who still, weirdly enough, kind of like one another at the end of the day. But a disproportionate number of season 5's episodes drop the hammer extra hard on Dee. This stands out, particularly because, in the early days, the series let its actresses embrace the same terrible behavior as their male co-stars. Too many sitcoms of the 2000s (and today) make their token female cast member a scolding wet blanket, and "Always Sunny" has always openly defied that trope. But because Dee doesn't get to lead that many of the season's plots — and because there aren't many episodes in which the guys, not Dee, take the biggest dive — the gender disparity ends up standing out more than usual.

While some of its early episodes are a bit rocky, season 13 is arguably the best of the post-10 era. "The Gang Makes Paddy's Great Again" is a brilliant play on the audience's well-trained ability to sense the show's rhythms, and addresses the issue of such a long-running series becoming predictable. "The Gang Does a Clip Show" starts with a standard take on the formula and devolves into the surreal. The two episodes that target "timely" subjects — specifically, the Me Too movement and discriminatory bathroom bills — have a stronger grasp of where they're going than season 12's experiments (though they're still noticeable for addressing cultural conversations that hadn't been in the spotlight for very long).

What pushes season 13 above and beyond are the three episodes that round it out. "Charlie's Home Alone" might be a better showcase of Charlie Day's physical comedy prowess than "Charlie Work," and the fusion of "Home Alone" and "Saw" is downright elegant. Its companion episode, "The Gang Wins the Big Game," is a little "Mr. Magoo" and a lot of endearing excitement about the Eagles, which bleeds over into an episode that feels like an ode to Philadelphia as a community. But the real grace note is the way "Mac Finds His Pride" manages to earn complete and utter sincerity in a show that's so frequently about how the characters hate each other (even if they also need one another).

This might be the show's first nearly perfect season. The cast dynamics are locked in, recurring side characters like Artemis, the McPoyles, and Cricket appear throughout, and it has an even mix of conceptually out-there episodes and installments that zero in on the relationships between the core cast members. But what really puts season 4 near the top is the one-two punch of "Sweet Dee Has a Heart Attack" and "The Nightman Cometh." The former birthed the iconic conspiracy board meme, while the latter remains one of the best episodes of "It's Always Sunny in Philadelphia," period. Beyond their utility as jokes, the songs are memorable and catchy, every character gets a moment in the spotlight, and the central set piece kills. It's also a crucial reminder that Charlie is, in fact, just as terrible as the rest of the gang.

More divisive is the period-piece parody "The Gang Cracks the Liberty Bell," which is as cartoonish as "Always Sunny" gets. While its framing device, in which the Gang builds on one another's lies in order to create a conflicting narrative, is a good one, it's better executed in later seasons. Still, there's a demented joy in the cast's dedication to the bit and their clear enjoyment of the period trappings. "Who Pooped the Bed?" finally gives Kaitlin Olson and Mary Elizabeth Ellis a chance to bounce off one another in a solid parody of drawing room mysteries, and "The Gang Solves the Gas Crisis" is a prime example of how skillfully "Always Sunny" escalates mundane situations into pure madness.