4. Danny DeVito Is A Dirty, Dirty Man
Danny DeVito was a fan of season one and joined Its Always Sunny at the start of season two as Frank Reynolds, Dennis and Dees father; although he is as much of a father figure as Darth Vader. This is Danny DeVitos perfect role. He plays a disgusting pervert so well its disturbing. Frank lives with Charlie in basic squalor their living arrangements are less than normal, they share a bed (the subject of the episode Who pooped the bed?) and play abnormal games such as the self-explanatory Night Crawlers. Frank is awful to his children, which is hilarious given how awful Dennis and Dee are to everyone else. He has no problem with using them for his own gain; he pimps Dennis out as a male escort and convinces Dee to become a boxer as part of a bet. But Frank gets really dirty when it comes to sex. His low standards and warped mind result in sordid stories that youll wish you could unhear but DeVito plays the character so faultlessly that its worth watching Its Always Sunny for him alone.