While everyone plays to each other's strengths in It's Always Sunny in Philadelphia, it's apparent that Danny DeVito was the key to the show's prolonged success. Having been introduced into the fold after the executives at FX were worried about the show's sustainability, it was revealed that Danny DeVito was the unexpectedly perfect candidate for the job, the one A-list talent who could be completely dirty and weird and gross in all the right ways that fit this show. Without Danny DeVito's commendable ability to do whatever it takes for the role, the show wouldn't last nearly as long. More importantly, it wouldn't be nearly as good, nor as consistently funny, as we know the show to be today. Bless you, Danny DeVito, for everything.