Alien was one of those perfect-storm movies where every decision just plain worked out right. Think about the cast for a minute: There are seven people (and one cat) in this movie, and every single one of them is absolutely perfect for the role they play. To wit:
Sigourney Weaver: Siggy invented the modern female action hero in this movie; Angelina Jolie should be cutting her in for at least 10% right off the top. As Ripley, Our Heroine, Sigourney (real name: Susan Alexandra Weaver) projects an amazing combination of strength, vulnerability, and unconventional/too-tall-and-skinny/just-slightly-butch sex appeal. Alien made Sigourney a star, but no other role ever allowed her to shine like this one (see also: Aliens and, on and off, the two other movies in the series); Ripleys don’t just come along every day.