Alien (1979)

After intercepting a distress signal from an unknown planet, one of the explorers of the commercial spaceship Nostromo is attacked by a deadly lifeform. In ignorance, the crew is unaware of the danger to their lives as an alien parasite capable of harboring itself inside the unfortunate wounded host boards the ship with them. Ridley Scott's direction effectively captures the emotional and psychological trauma of the situation, creating an atmosphere that is both stimulating and terrifying.