The recently concluded third season of FX's It's Always Sunny in Philadelphia is definitely the most popular, although I don't think the ratings are exactly spectacular. But after being almost entirely obscure in its first season and only slightly less so in its second (despite the presence of Danny DeVito), it's become the go-to cult comedy hit, right behind 30 Rock in blogosphere and message-board popularity (this is based entirely on anecdotal evidence and is possibly in no way accurate). FX promoted the hell out of this season, and finally released the first two seasons on DVD; although they haven't announced a fourth-season pick-up, it seems far more likely than it was in the past.
And yet this was easily the show's worst season, one in which it really seemed like they were running out of ideas, in which the already ridiculous characters each became simply exaggerations of their one defining trait, and one in which DeVito's character was revealed to be entirely useless. It was also still very funny, and more daring than just about any comedy on TV, but I can't help but think that in the network's zeal to have more of the show that everyone's talking about, they've diluted what made it worth talking about in the first place.
The seven-episode first season was basically put together by actor/writers Rob McElhenney, Glenn Howerton and Charlie Day on their own, and the 10-episode second season had only two episodes with contributions from other writers. But this season's 15 episodes were penned by a variety of writers (still including the three stars), and it really seemed to me that the increased number of episodes stretched the show's creative resources too thin. The initial appeal of the show was in how it broke so many different taboos in each episode, but now that most of the obvious appalling ground has been covered, all that's left is for the plots to become more and more ridiculous, the characters less and less human. At first, they seemed to be clever exaggerations of the worst in human nature, but now Dennis' vanity, Mac's competitiveness, Dee's insecurity and Charlie's simple-mindedness have been distorted to the point of distraction. (Although admittedly I will never find Charlie's illiteracy not funny.)
Last season's development of narrative continuity was a welcome change, but this season the dynamic between DeVito's Frank and his pseudo-children Dennis and Dee was basically abandoned, and he just became another one of the gang, and thus entirely superfluous. After discovering at the end of last season that Frank wasn't their actual dad (and that he probably was Charlie's), Dennis and Dee seem to have just decided to treat him like some guy they met, and the possibility of his relationship to Charlie was never really developed. Still, there were plenty of recurring characters and nods to past storylines, most of which paid off well (the McPoyles are best in small doses, but I was happy for the returns of The Waitress, Mac's dad and Stephen Collins as Dennis and Dee's real father, the only good person ever to appear on the show).
If FX does bring the show back for another season, I hope they'll reduce the order to a more manageable number, and that the creators will find a compelling new ways for the characters to relate to each other rather than just stand around in the same place reacting to the plot of the week. The early episodes were so funny as much because of their surprising newness as anything else, but like any show whose novelty wears off over time, Sunny needs to find a way to sustain itself long-term with more than just increasingly desperate attempts at shock. From this season at least, I'm not sure if they'll make it.