It's Always Sunny In Philadelphia: 10 Best Recurring Jokes

10. Charlie's Characters

Charlie Kelly is an easy fan-favourite for the show, and one of the best things to come from the squeaky-voiced janitor is his plethora of weird characters. The main ones being The Nightman, The Dayman and Green Man.

Firstly, Green Man is always a funny thing to see, as Charlie's green morph suit, which he uses as a sports mascot, has led to some great moments, such as Charlie fighting the Philly Fanatic and Cricket using it to gate-crash the gang's Superbowl adventure. It's a great recurring joke that only appears every so often.

However, the Day and Night man characters take this even further, as they don't seem to be roles he made up, but rather deep emotional presences in Charlie's psyche.

It's abundantly clear that Charlie is dealing with some traumatic emotional problems. Those always seem to manifest as The Nightman, a character who the gang clearly see as a person who assaulted him, as the lyrics of his song makes clear. While the reality of these characters is horrible, it's also hilarious as their constant mention shows how close Charlie always is to cracking.

Plus, who could ever forget "The Nightman Cometh"? Best musical episode ever.