The Shining
Considered one of the goat horror movies and for very valid reasons. Kubrick is considered one of the goat directors and for very valid reasons. Jack Nicholson is considered one of the goat actors and very for valid reasons. This film is such a staple in the film industry. Master of suspense and drama, and building up the characters to where you care what happens in the third act.
Really hard to find any flaws with this one, and so easy to tell why it has become such an iconic movie.