They say laughter is the best medicine, and the 20 greatest comedy masterpieces of all time took that saying seriously. They haven't just made people laugh, but they continue to heal something within them, either by awakening nostalgia for a better time or simply being funny enough to ward off negativity.
It's hard to pick a specific list of the best comedies of all time because that can be highly subjective, but some have defined the year or even the decade they were released in. As with any good and engaging movie, most of them are somehow reflections on society or parts of it that are rarely discussed candidly or openly, from M*A*S*H to Monty Python and the Holy Grail, these are the greatest comedies of all time.