It may not have its own category at the Oscars, but watching a comedy is one of the most communal experiences one can have at the movies. From Buster Keaton's pioneering pratfalls and Jim Carrey's outlandish antics, to Tina Fey's whip-smart dialogue and Eddie Murphy's trailblazing sense of humor, there's no genre that has transformed through the years much like comedy. We discuss who and what makes us laugh, political correctness in comedy, and the movies and TV shows that will never stop being funny.