One of the scenes of Alien: Resurrection involved Ripley making a basket after throwing it over her shoulder with her back to the rim. The intention was for Sigourney to just throw the basketball and the crew would make it look like she made it after editing. Sigourney made the shot on the first try. Unfortunately, the crew was forced to reshoot the scene after Ron Perlman, understandably, broke character in pure shock.
Her performance as Ripley in Aliens, which was powerful and iconic enough to earn a Best Actress nomination. As an action hero from a science fiction movie, a genre that The Oscars routinely snubs in the acting categories both male and female.
Being cast as the Big Bad of The Defenders, which Jeph Loeb describes as the result of a long and hard search for an actor you could believe it would take all four Defenders to take down.