: Creators Rob McElhenney, Glenn Howerton, and Charlie Day used their own digital cameras and apartments.

The show’s origin is as scrappy as the characters themselves.

: The chemistry works because the cast are real friends; Rob McElhenney and Kaitlin Olson (Dee) are actually married in real life. Why It’s "Seinfeld on Crack"

Critics often call the show "Seinfeld on crack" because it takes the "no hugging, no learning" rule to a terrifying extreme.

With a staggering and over 16 seasons under its belt, it is officially the longest-running live-action sitcom in American history. The $85 Pilot That Changed Everything

(the Portuguese title for It's Always Sunny in Philadelphia ) is the ultimate "anti-sitcom." While most comedies from 2005 featured lovable friends who learned life lessons, this show introduced us to five of the most narcissistic, depraved, and hilarious people on television.

: The original pilot was shot for less than $100—some estimates say as little as $85 .