Introduced in the premier of Season 2, Frank Reynolds is the reason whyIt’s Always Sunny in Philadelphiais not only well-known, but TV’s longest-running live-action sitcom. Of course,Sunnyis no ordinary sitcom, with a looseness that makes it easy to see why Danny DeVito was interested in the first place.

And make no mistake,Sunnywouldn’t be a thing without DeVito. It also wouldn’t be nearly as good without his character, who has enjoyed his descent into the world of “Bangin' wh***s” and general overall depravity. And then there’s watching Frank and Charlie bond, which has consistently proved to be one ofSunny’s greatest dynamics. Furthermore, it’s remarkable both how many different wild things Rob McElhenney, Charlie Day, and Glenn Howerton come up with for the character and how willing an actor of DeVito’s caliber is to play along. Like Frank, he’s truly a member of the Gang.

The Gang Gets Invincible

20"The Gang Gets Invincible" (Season 3, Ep 2)

Of all theSunnyepisodes to reference a movie, “The Gang Gets Invincible” is about as direct as they get. It’s also an early example of two things: The show breaking away from the bar for an entire episode and Frank Reynolds going further down the drug-fueled rabbit hole.

Frank’s experimentation with LSD is the funniest aspect ofInvincible, which is one of the elongated third season’s best entries. His hazy waving of a gun and blurting of “That lizard talks!” are incredible, but better yet is his thinking he’s locked in a bathroom just because he’s stepped into a garbage can. The episode is important for the development of Frank’s character in another way: Artemis. Her looking on as he stumbles in the trash can is their first pairing, and it’s a pairing that would continue throughout the series' run.

The Nightman Cometh

19"The Nightman Cometh" (Season 4, Ep 13)

It’s Always Sunny in Philadelphiais one ofthe best series on Hulu, and Season 4’s finale, “The Nightman Cometh,” is all the proof one needs. A masterpiece from front to back, the episode is buoyed by McElhenney, Howerton, and Day’s razor-sharp script and director Matt Shakman’s (Director of the MCU’s impendingFantastic Four) mastery of pacing.

It’s also a pretty darn good musical Charlie’s written. Horrifying and illuminating, but good. Not to mention, the fact he wrote it all thinking it would be the thing to win over the waitress is at one time charming, in character, sad, and obviously destined to fail.

The Gang Gives Frank an Intervention

18"The Gang Gives Frank an Intervention" (Season 5, Ep 4)

It’s Always SunnyisTV’s longest-running live-action sitcom, which is a truly impressive accomplishment. And, again, it’s hard not to feel thankful to Danny DeVito’s star power for that.

For those who haven’t experienced the show and think it’s nothing more than crass vulgarity, “The Gang Gives Frank an Intervention” is the episode to show them. Is it crass? Sure. But the characters' crassness does absolutely nothing for them, and it’s somehow more stone-cold hilarious than usual. For one, there’s the wine in a can. But then there’s the best scene to ever come fromSunny, where Frank is walking down a desolate suburban street “blitzed” out of his mind, going in and out of even realizing Mac is walking by his side.

the gang wrestles for the troops

17"The Gang Wrestles for the Troops" (Season 5, Ep 7)

A top-tier episode not just for Season 5 (widely considered the series' best) but forIt’s Always Sunnyas a whole, there’s never a dull moment in “The Gang Wrestles for the Troops.” It’s also the episode to introduce Ben the Soldier, and thanks to Travis Schuldt’s lovable performance he’s immediately one of the show’s best guest stars.

Dee, of course, gets most of the big moments with the character, but Frank has a moment of respect as well. Specifically, as he salutes the young man (to whom he’s just gifted a pair of jean shorts) while Seal’s “Kiss from a Rose” blasts on a boombox just behind him. It’s one of Frank’s most iconic moments, but it’s arguably not even the character’s funniest moment in the episode. That’d be when he enters Paddy’s Pub with the massive clang of a thrown trash can and an exclamation about being “The Trash Man!”

The Gang Gets Stranded in the Woods

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16"The Gang Gets Stranded in the Woods" (Season 6, Ep 11)

Each season ofSunnyis notablefor an individual reason, and for Season 6 it’s the fact that it was the first to be shot in HD. It also took the Gang away from Paddy’s.

That episode, “The Gang Gets Stranded in the Woods,” is fairly average for the series, but it’s a lovely one for Frank. As for the episode as a whole, Charlie’s fear of leaving Philly had been covered in the previous season’sThe Gang Hits the Road, and his and Dennis' trip to Vegas on Frank’s dime (where they meet Chase Utley, much to Mac’s chagrin) is funny but unspectacular. The same could be said of Dennis, Dee, and Frank’s being stranded in the woods, but there’s little doubt Frank’s stare down with a rabbit (and subsequent change of heart on animals) is a nice exploration of his sensitive side.

15"Frank’s Pretty Woman" (Season 7, Ep 1)

The real highlight of “Frank’s Pretty Woman” is Alanna Ubach’s work as Roxy, but she’s also just one of many reasons the episode is one of the series' most rewatchable. Charlie and Frank’s plot, where the former attempts to set the latter up with a woman classier than Roxy, is a particularly strong thread.

For instance, as funny as it is to see Charlie accidentally vomit up fake blood on a screaming, unsuspecting woman, that’s not what makes the bit so amazing. What makes the bit so amazing is Frank’s sincere question of “Can I offer you a nice egg in this trying time?”

14"The Gang Goes to the Jersey Shore" (Season 7, Ep 2)

While “The Gang Goes to the Jersey Shore” featuresa great Charlie Day performance, it’s Frank Reynolds who runs away with the episode. Whether it’s his hollering of “Rum Ham! Rum Ham!” or his partying with “the Guidos!,” Frank (and by extension DeVito) appears to be having the absolute time of his life throughout their journey to the Jersey Shore.

Mac and Frank aren’t usually paired up, but this Season 7 episode revels in the match. Once the two end up on a needle-ridden beach, it’s pretty obvious they’re going to get into some stuff. Fortunately, that stuff is more fun than the contents of Dennis and Dee’s evening.

13"Frank Reynolds' Little Beauties" (Season 7, Ep 3)

Easily one ofIt’s Always Sunny’s funniest episodes, every scene in “Frank Reynolds' Little Beauties” is gaspingly funny. The audience fully believes that Frank would throw in for a beauty pageant just hoping to “ogle” some women just as they believe he wouldn’t do his due diligence regarding the age of the contestants.

Frank’s efforts to distance himself from his now-incarcerated “diddler” of a business partner are the episode’s highlight. On one hand, there’s his constant declaration that his dressing room is on the opposite side of the area than the children’s. On the other there’s his post-mortem makeup and the mortician who applied it. Neither one helps.

12"The Gang Gets Analyzed" (Season 8, Ep 5)

In no universedoesIt’s Always Sunnyneed a movie, because the show has consistently found ways of expanding its characters' life stories in ways that are so bizarre they reek of a movie pulling off what a show could not (for exampleSouth Park: Bigger, Longer & Uncut). “The Gang Gets Analyzed” manages to be that extra-deep deep dive without a longer runtime or more exclusive rating.

It’s a solid episode, with a few good gags for Mac and a solid bit where Charlie keeps a (now-suffocated) pigeon in his green jacket, but it’s Frank who ownsAnalyzed. His screaming of “You unzipped me!” is an all-timer, as is his long story about the “Frog Kid,” Frank’s buddy at the “Loony Bin.”

11"Mac and Dennis Buy a Timeshare" (Season 9, Ep 4)

If there’s an official top five images of Frank Reynolds floating around out there, there’s no doubt him being trapped in the coil in “Mac and Dennis Buy a Timeshare” is on there. Frank has the least amount of screentime in the episode, yet he runs away with it.

The sight of Danny DeVito in his tighty whities inexplicably jammed within a group of bars is laugh out loud funny no matter how many times one watches the episode. The fact that it’s never explained? Even better.