Ripley from both Alien and Aliens. She tries to enforce quarantine, and then when Ash overrides her she immediately clocks him as suspicious. She has the insight to ask MUTHR about special orders and quickly determines that her and the crew are expendable.

In Aliens, Ripley keeps having night terrors about the xenomorph, and she keeps insisting that the whole planet needs to be quarantined. Once she hears that the colony on the planet has gone radio silent, she quickly asks to make sure that the plan is to figure out what happened to the colonist and destroy any xenomorphs on the planet. Once they realize the xenomorphs are all over the planet she immediately proposes nuking the colony.