4. The Exorcist (1973)
One of the most famous and scary Horror films of all time, The Exorcist was a global smash hit that terrified the crap out of millions of cinema goers in the 1970s. Dealing with the theme of demonic child possession, the film packed little punches and there are a variety of controversial scenes I could have had my pick of. But the most controversial and disturbing scene that stayed with me was when 12 year old Regan (Linda Blair) self abused herself with a crucifix screaming "Let Jesus F**k you! Let Jesus F**k you!". Cinema audiences nowadays are used to all sorts of nefarious goings on. Back in the 1970s, for audiences to hear those words and see that action must have been a full out assault on the senses. Blasphemy was a big deal back then, especially from the mouth of a 12 year old girl. Even today, it retains its power to shock.