1. Don't Look Now (1973)
Not only one of the greatest horrors of all time but one of the greatest films ever made, Nicolas Roeg's Don't Look Now takes the giallo hallmark of hallucinatory images and weds it to a profound examination of the effects of deep psychological grief. Anchored by a tremendous performance from the brilliant Donald Sutherland, Don't Look Now spins a fable about how the sudden death of a child effects the bond between an emotionally distant architect, John Baxter (Sutherland), and his wife, Laura (Julie Christie). After the tragic drowning of their young daughter, the couple travels to Venice where John has been contracted to restore an ancient church. Soon after, Laura becomes convinced a blind psychic can communicate with the couple's deceased daughter. The sceptical John refuses to believe his wife's story until he starts seeing a mysterious child-like figure, wearing the same red mackintosh his daughter wore the day she drowned, haunting the streets of Venice. John decides to track down the apparition with tragic results. Equal parts heart-breaking tragedy and unnerving horror parable, Don't Look Now should be required viewing for lovers of cinema in general not only horror enthusiasts. Let me know in the comments what must-see horror classic I missed. I'm always looking to watch a great one.