It's Always Sunny In Philadelphia season 13 was arguably the show's weakest to date - but it also featured the best episode. It's Always Sunny In Philadelphia debuted in 2005 and is a pitch-black sitcom following the group of misfits running Paddy's Pub. They are - by turns - selfish, sociopathic, insecure and downright cruel, and most of their schemes are ill-conceived and destined to fail.
Despite the fact they're all horrible there's something strangely lovable about the It's Always Sunny In Philadelphia gang, which is down to the chemistry of the cast, including Glenn Howerton, Kaitlin Olson, and Charlie Day (Horrible Bosses). In light of the show's longevity, it's hard to believe it was on the verge of cancelation after its first season, so Danny DeVito was added for some star power. This worked a treat and It's Always Sunny In Philadelphia has lasted fourteen seasons and counting, making it one of the longest-running sitcoms of all time.
In most successful sitcoms - like Friends or The Office - there's a comfortable formula, and while the characters grow ever so slightly over time, there tends to be a repetition in storylines. What's remarkable about It's Always Sunny In Philadelphia is how little the gang have grown as people. They just as petty and miserable as the first season and age hasn't brought wisdom. That said, Mac (Rob McElhenney) has shown the most growth, with later seasons heavily hinting he's gay. He finally came out in season 11 after years of denying it to himself and others, and his struggle to tell his father would serve as the basis of It's Always Sunny In Philadelphia season 13 episode "Mac Finds His Pride."
Sadly, It's Always Sunny In Philadelphia season 13 is probably the weakest season. It features several misfiring episodes like "The Gang Does a Clip Show" or "The Gang Wins the Big Game." It still featured gems like "The Gang Escapes," but there was a sense of wheel-spinning to the season that was disappointing. That's why season finale "Mac Finds His Pride" was such a pleasant surprise, which finds Mac struggling to find his place as a gay man and to come out to his convict father. Naturally, Frank Reynolds (DeVito) is the worst possible person to help him with this and belittles Mac's struggle throughout.
What makes "Mac Finds His Pride" so great is that it takes Mac's struggles seriously, and the finale sees him admit to his father he's gay and then performing a seriously impressive dance number. In addition to explaining why Mac was suddenly so damn buff throughout It's Always Sunny In Philadelphia season 13, its a sequence utterly unlike anything else the show has attempted. It's genuinely moving, especially when Mac's father leaves halfway through but a distraught Mac still finishes the routine, and it even makes Frank cry when he finally understands what Mac is going through. The season as a whole wasn't the show's best, but it's impressive that even after thirteen seasons, it can still deliver arguably the show's best episode yet.