"The gang" on "It's Always Sunny in Philadelphia" are five of the most extreme, ridiculous, poorly behaved people in television history. While the show is so much more than just a show about terrible people, it is admittedly populated by some pretty awful human beings. Charlie (Charlie Day), Mac (Rob McElhenney), Dennis (Glenn Howerton), Sweet Dee (Kaitlin Olson), and Frank (Danny DeVito) are pretty entertaining all on their own, but they also have to interact with other people, which means expanding the "Always Sunny" world with more weird and wild characters. There are dozens of recurring characters that appear throughout the show's 16 seasons, but some of them have made their mark more than others, either as willing accomplices in the gang's schemes or as their unfortunate targets.

There aren't really many decent people who engage with the gang for long without being broken or simply bailing on the situation, so...