Determining the scariest movie is subjective, and different people may have different opinions. However, according to various sources, some of the scariest movies ever made are:

• The Exorcist (1973): This movie is about a demon-possessed child and the attempts to banish the demon. It became the highest-grossing R-rated horror film ever and the first to be nominated for Best Picture at the Oscars.

• Hereditary (2018): This movie is about a family haunted by a mysterious presence after the death of their grandmother. It received critical acclaim for its performances, direction, and atmosphere.

• The Conjuring (2013): This movie is about paranormal investigators who encounter demonic possession. It is considered one of the most horrifying films of all time.

• Sinister (2012): This movie is about a non-fiction crime writer who moves his family into a house where gruesome murders took place. It is considered by many to be the scariest modern horror film of all time.

• Goodnight Mommy (2014): This movie is about twin boys who suspect that their mother, who has undergone cosmetic surgery, is not their real mother. It is known for its creepy atmosphere and delicate pace but also has excessive torture scenes.

• The Innocents (1961): This movie is about a governess who takes care of two children in a remote mansion and begins to see ghosts. It is considered one of the scariest movies ever made.

• Insidious (2010): This movie is about a family who moves into a new house and begins to experience supernatural events. It is known for its jump scares and creepy atmosphere.

• Paranormal Activity (2007): This movie is about a couple who set up cameras in their house to capture evidence of a demonic entity that they believe is terrorizing them. It is known for its found-footage style and suspenseful build-up.

• The Babadook (2014): This movie is about a single mother who is haunted by a mysterious creature from a childrens book. It received critical acclaim for its performances, direction, and themes.

• The Texas Chain Saw Massacre (1974): This movie is about a group of friends who encounter a family of cannibals while on a road trip. It is known for its graphic violence and disturbing imagery.

Overall, the scariest movie is subjective and depends on personal preferences. However, these movies are known for their ability to terrify audiences and have become iconic in the horror genre.