Top 10 It's Always Sunny In Philadelphia Episodes

The title gags are a staple of It's Always Sunny, and this is one of the best examples, as Dee adamantly states there is no way she is dating a retarded person, and the title serves as a gag correcting her. Amazing.

As Dee tries to determine whether or not her new boyfriend is mentally challenged, the guys start an ill-informed, uncoordinated band, and Charlie gives birth to the infamous 'Nightman' and 'Dayman' songs, running jokes in the series and fan favourite songs, that stem from the disturbing idea that Charlie was sexually assaulted as a child.

This episode is rightfully a classic, as it combines the show's musical aptitude with its trademark dark humour perfectly, with the two story strands combining in a perfect finale, where Charlie and Dennis, shunned by Mac and Frank, form their own group, and Dee, after finally popping the unusual question to her boyfriend and asking if he is, in fact, retarded, make for an unforgettable final twist.

With every character's ego on full display and tested in their own way, the character work here is some of the series' best, and that is high praise given how consistently great the character work is.