Alien

Alien (1979) merges visceral horror with sci-fi so seamlessly that it remains a benchmark for the genre 47 years later. The chestburster scene, filmed in one continuous take using $200 in prosthetic materials, captures Veronica Cartwright's authentic scream — a reaction that no rehearsed scare can replicate. H.R. Giger's biomechanical design cost $1.5 million of the film's $11 million budget, creating a creature that unnerves even in daylight.