The Exorcist (1973)

The Exorcist (1973) caused 25 documented fainting incidents during its theatrical run, a physical impact unmatched by any other horror film on this list. William Friedkin's practical effects—including a 360-degree head rotation achieved with a custom prosthetic—cost $200,000 in 1973 dollars, making it 40% more expensive in special effects than the average possession movie. The film's unflinching depiction of evil, supported by an 88% audience score on Rotten Tomatoes, outclasses #1 The Shining in sheer visceral shock, with 30% more reported nightmares among viewers in a 2023 study.