In our current franchise-dominated landscape, it's hard to imagine an actor having the brass to insist their character be killed off. But that's what living legend Sigourney Weaver did when she made 1992's "Alien 3," reasoning that her "Alien" heroine — the plucky blue-collar space trucker turned badass Xenomorph slayer Ellen Ripley — had endured more than her fair share of bad luck by that point. She would backtrack on that five years later for "Alien: Resurrection," intrigued by the idea of reprising not the Ripley we knew and loved, but a hybrid alien/human clone with her own quirks and personality (not to mention a killer behind-the-back basketball shot). Weaver would then come precariously close to reprising Ripley proper for Neill Blomkamp's scrapped "Alien 5," a sequel that, in a stunt similar to the one David Gordon Green's "Halloween" pulled, planned to ignore the prior two sequels by taking the...