The New York Times has been running a long self-congratulatory series of essays, tied to the upcoming 100th anniversary of Stravinsky's Le Sacre du Printemps, called "Shock Value" about art that shocks in which various culture mavens talk about how they got over their bourgeois hangups to appreciate this or that now approved movie or painting.
But what about unapproved movies?
In this century, objectively speaking, the most shocking movies to the Establishment, as measured in efforts to kill them, were likely The Passion of the Christ and Idiocracy. (Consider how the studios and media marketed Borat v. tried to drown Idiocracy like a kitten.)
But, honorable mention should be made of a 2009 movie that was so gut-punch shocking that almost nobody noticed it, the plot was so far outside the realm of acceptable thought: Disgrace, an adaptation of the 1999 novel that won J.M. Coetzee the Nobel Prize in Literature in 2002, and caused him to flee South Africa for safety in Australia after the ruling African National Congress objected to his Nobel. John Malkovich played a South African professor who is powerless to prevent his lesbian daughter from being gang-raped and then incorporated as a junior wife into a black peasant family.