Alien (1979)

Alien (1979) redefined sci-fi horror by stripping away genre reassurances, replacing them with the inescapable terror of being hunted in a sealed space, winning the Academy Award for Best Visual Effects. H.R. Giger's biomechanical creature design and Ridley Scott's practical effects provoked genuine shock from cast and audience, with the chest-burster scene causing 3 reported fainting incidents during initial screenings.