Although I label this as a'MUST WATCH' movie to all you horror fans, consequently, I must also warn you. Through the majority of reliable and trust-worthy sources, this is rated, by people all over the globe, as the scariest film in existence. I too, agree. I mean, for it to have been made in 1973 is absolutely unbelievable due to the quality filming and the insuppressible nerves it shocked me with. This is my last warning: Do Not, I repeat, Do Not watch this film if you are uncomfortable with movies which express the control Satan or spirits can have over our body, and if you like 'tame' horrors, as this will destroy you and possibly your sleep for the rest of your life.
Anyways, enough of the emphasis on how scary it is (although it must be addressed), it is a remarkable film, lasting a long 122 minutes full of intensely frightening, yet intriguing and possibly (to you) very disturbing scenes.
The film, directed by William Friedkin, revolves around a young actress named Chris McNeil (Ellen Burstyn) who notices the scripting for the film she is starred in seems inadequate. Father Karras (Jason Miller) begins to lose faith as they his is dealing with a sick mother and he believes he cannot afford to money in order to care for her. At this point, Chris McNeil also notices strange behaviour from her daughter Regan (Linda Blair). Regan begins to brutally change both in appearance and behaviour, therefore leaving Chris only with the option to call a priest. Soon enough, Regan begins to have intense violent moments with anyone who makes contact with her or comes near her, leaving the priest with the only solution but to assume she is possessed. From this, and down to the poor faith in Father Karras, Father Merrin (Max Von Sydow) is introduced in order to deal with an exorcism on the suffering Regan, and hopefully to remove the spirit from her.
I won't ruin anymore now, but from this moment, the film becomes very violent, disturbing and intensely frightening due to the savaging actions of the young Regan as she is controlled by evil spirits. I would NOT recommend this film for the faint-hearted, and due to the horrors you will face - I am NOT exaggerating. However, aside the fear driven through us, the film is fantastic in terms of the plot / story line. It has its intriguing moments, and somehow creates a sense of mystery through me. I also must mention that I feel this horror is a whole lot scarier than The Exorcism of Emily Rose - http://horrorfilmz4you.blogspot.co.uk/2014/05/friday-night-special-exorcism-of-emily.html , as it is an exorcism at a present tense rather than a court case, and you see a lot more footage of the actual exorcism.
Therefore, in addition to the 'Must Watch' - The Shining - I would also wish to enforce my personal view across that I believe for a true horror fan, this film should be your top priority to watch.
However, just remember how much I am emphasizing how scary it is! What I also find impressive is the year it was made. Similarly to The Shining, it has very impressive special FX and is also impressive in terms of how frightened I was at several points!
Overall, I must say, I need to stop here as I could literally talk all day about this film, but all you need to remember about it is that it is a MUST WATCH - horror classic!