At this point, It's Always Sunny in Philadelphia is one of the longest-running sitcoms ever. With fourteen seasons and a fifteenth on the way, the show doesn't appear to be slowing down anytime soon.
Many shows that have been on for as long as this one might have seen a drop in the quality of the writing, but not It's Always Sunny. While there may be the odd weak episode here and there, this show is still consistent in delivering laughs and doubling down on its characters' perpetual awfulness.
Season Six - 94%
Kaitlin Olson was pregnant during the filming of season six, so the show occasionally uses Dee's pregnancy as a plotline. It's even funnier, however, how the self-absorbed group more often fails to notice any changes happening to their friend at all.
When they make fun of her for getting fat, Dee accuses one of them of being the father, causing them to take notice and try to piece together a drunken night that might have led to Dee getting pregnant. Once she tells them it isn't one of them, they go back to insulting her and not caring at all about her or her unborn child. Since the guys don't ask too many questions, the day of the delivery has them scrambling to figure out who the father is, which leads to Frank partying with "the usual suspects."
Season Five - 94%
Season five has a lot of great episodes. We meet Dennis and Mac's real estate alter egos, Hugh Honey and Vick Vinegar, and Charlie's complicated relationship with lawyer-ing begins. It's this season that we also learn that Charlie has never left Philadelphia or eaten a pear—or a surprising number of other fruits.
Frank decides that, since he only has one life, he's gonna "get weird with it" and tries to have sex with his recently widowed sister-in-law, but he ends up getting mashed by Gail the Snail (you don't want to know what that means). We also meet Jean Shorts Soldier, and Charlie comes up with "Kitten Mittens" for a quieter cat. Finally, season five introduces the D.E.N.N.I.S. system, as the show continues to reveal deeper layers of his depravity.
Season 13 - 94%
Season 13 is perhaps a bit underrated. It features an escape room game that reveals that Dennis is, in fact, a psychopath. The gang attends a Time'sUp seminar that contorts their views on sexual assault and causes them to realize that stalking is not, in fact, romantic. A fan favorite for many is "Mac Finds His Pride," wherein the show makes a rare choice to be a bit serious in its handling of sexuality.
Season Two - 95%
Season two made an automatic improvement by bringing on Danny DeVito as Frank, Dennis, and Dee's dad—sort of. This season features Charlie going full Lieutenant Dan, Dennis and Dee getting addicted to crack in an attempt to receive welfare, and an excellent Million Dollar Baby parody. It also marks the first time we meet Rickety Cricket, and Dee instantly sets him on a downward spiral that he's still on as of the latest season. Rock, flag, and eagle.
Season 11 - 100%
In one of the more successful examples of the show returning to an old plot, the gang plays Chardee MacDennis again, which Frank retitles "Chardee MacDennis 2: Elictric Boogaloo."
The horrors of the suburbs are hilariously explored when Mac and Dennis try their hand at suburban life. Charlie gets high on paint and thinks he's caught a leprechaun on St. Patrick's Day, and the gang thinks they've died and gone to hell when they're locked in the brig of a cruise ship.
Season Eight - 100%
Season eight has a ton of standout moments. The Maureen Ponderosa wedding turns into a zombie attack, and an argument over who has to do the dishes results in the gang going to Dee's therapist. There, it's revealed that Dennis is secretly drugging Mac to prevent him from getting fat again, Charlie carries a dead pigeon around in his coat, and Frank spent time in a mental institution.
"The Gang Dines Out" is another great episode wherein Mac and Dennis, Frank and Charlie, and Dee, separately turn a coincidence during a night out into a power struggle. Finally, an impromptu trial in the bar has Mac getting everyone to be "on the fence" about evolution.
Season Seven - 100%
Season seven is easily recognizable as the one where Mac gets fat. It's also the one where we meet Roxy (gone too soon), Charlie vomits copious amounts of blood, and Dee briefly considers becoming a foot girl. A trip to the Jersey Shore results in rum ham, spray tans, and murder.
Frank accidentally agrees to host a children's beauty pageant and desperately tries to prove that he's not a creep. The gang teaches Frank how to play Chardee MacDennis, and a race across town to catch a showing of Thunder Gun results in Frank stealing a boat and Dee being covered in feces. The season ends with the gang attending their high school reunion, realizing that they will never be cool, and dancing to Freedom! '90.
Season Four - 100%
Let's break down season four, shall we? Mac and Dennis hunt Rickety Cricket, while Frank insists that he actually lived through the events of Rambo. Later, Mac and Charlie fake their deaths and get hooked on poppers in the process, all in an attempt to hide from Mac's dad, who doesn't actually want to kill them.
A mystery surrounding a turd in Charlie and Frank's bed leads to a full-on investigation being launched, and the gang kidnaps a reviewer who wrote a negative review of their bar. Sweet Dee has a heart attack, Charlie, Mac, and Dennis try to get historical landmark status for the bar on the basis that it was the site of the cracking of the Liberty Bell, and, finally... the nightman cometh.
Season 10 - 100%
In perhaps one of the best opening episodes of the series, the gang tries to beat Wade Bogg's record of drinking over 70 beers on a cross-country flight. Charlie gets his best Charlie-sode with "Charlie Work" in which he frantically tries to get the bar ready for inspection from the health inspector.
Frank's choice to retire leads to the gang draining buckets of his blood to prove who's next in line to take over the bar, of course, and Mac and Charlie join a cult made up by Dennis.
Season Nine - 100%
Kaitlin Olson kicks this season off with a great performance in "The Gang Broke Dee." The show goes meta when the gang tries to win a "best bar" award, leading to conversations about why the series never wins anything and doesn't try to be likable.
While the rest of the gang get roped into pyramid schemes, Frank is inexplicably stuck in a coil at a playground, wearing only his underwear. During "Mac Day," we meet Country Mac, Mac's much cooler cousin who jumps from a bridge as Frank goads him on.