In my humble opinion, there is no sitcom better than It's Always Sunny in Philadelphia. The trio of creators, Charlie Day (Charlie), Glenn Howerton (Dennis), and Rob McElhenney (Mac) have created fantastic relationships with debauchery. The only shows that come close are Seinfeld and Curb Your Enthusiasm, Larry David being the connection between the latter two. It's Always Sunny even had the tagline of "Seinfeld on Crack" early on its 11 year run. The show thrives on the adventures and lives of deplorable people and for me it hasn't lost a step, so I've decided to pick the best episodes from each season.
Season 1: The Gang Gets Racist
The line "How's that ass feel?" was the funniest and most shocking thing I saw on television back in 2006. I'd never seen anything like it. The characters were unashamed, uninformed, and completely racist. It was refreshing and hilarious. Also, it's the first time we meet these characters as little seedlings of societal pariahs before they continuously worsen.
Season 2: The Gang Gives Back
I specifically remember having a sore abdomen from laughing so hard. This may be the most consistently hilarious episode of the entire series. Season 2 is where Danny DeVito joins to essentially rescue the show from being cancelled, but he's not a buffoon yet, just a huge jerk. Anyway, this episode has the gang involved in mandatory community service, working as coaches for a Boys & Girls Club-like organization. Dennis tries to assemble an all African American team, Dee and Mac fight over who's the head coach, Frank buys a kid off for gambling, and Charlie suits up as a referee who occasionally blocks the kids' shots. The game itself ends up being a brawl because that's all the kids were taught and the gang ends up on trash detail. A perfection of a$$holery.
Season 3: The Gang Gets Held Hostage
Almost every season, some instance from the last year comes and bites them in the ass. Well, for Season 3 it's the incestuous McPoyles claiming their revenge. They lick. They stab. They drink milk. The McPoyles hold the gang hostage after they ruined a family member's chance to be on the Philadelphia Eagles. Every run in with these freaks results in at least one chuckle, and since they are at the centerfold of this one, the laughs are plenty. Particular standout moments are Dee's Stockholm Syndrome, and Frank crawling through the vents a la Die Hard.
Season 4: The Nightman Cometh
Was there any other choice? Actually there was. Who Pooped the Bed? and The Gang Gets Extreme: Home Makeover Edition were heavy contenders. Season 4 overall is one of their best. The winning factor, however, was the fact that the cast even toured and performed this Charlie musical for real, which is beyond ridiculous. Charlie is the star of this piece, whether he's getting fed up with the cast (mostly Dee), or when we find out he put on the whole thing just for the Waitress, it elicits tears of joy. The quality of the stupid songs, which the gang understandably misinterpret, is another high point.
Season 5: The D.E.N.N.I.S. System
Another legendary episode that I could not pass over, from a notoriously strong season. Dennis is in full sociopath mode, as he explains his methods of picking up women. It's daring even for today's standard, and it was a huge moment from the show that got a lot of people talking.
Stay on the lookout for Part 2!