Don't worry, we will never spoil anything pre-jump, though obviously everything after the break is operating under the assumption you've seen the film at hand, so be warned. And a big tip of our hat to Arbogast on Film for inspiring us with his post The One You Might Have Saved.
To see whose fate I would've altered in 2008's jungle boogie The Ruins, read on...
Name: Amy (played by Jena Malone)
Fate: Drives away in a Jeep, unscathed, after witnessing the death of all of her closest friends at the hands (vines?) of super-intelligent flora.
Verdict: Death to Amy!
Reason: In Scott Smith's novel, she's devoured by vines, just like the rest of 'em. Sure, this makes the novel impossibly bleak, but that's kind of the point. What makes The Ruins such a great read is that by the end of it, you're shell-shocked, and Smith managed to make you feel this way through one of horror's hokier threats -- the killer plant.
In the film, there's no good reason to leave Amy alive. Does The Ruins feel like it has a happy ending because she manages to drive away safely? Not at all. By leaving a survivor, The Ruins weakens the threat of the novel, and completely wastes Smith's original pitch black ending (which is especially odd, since he wrote the screenplay). The whole thing smacks of a lousy studio note.
(Editor's Note: This "Saved/Killed" only reflects the ending of the theatrical cut of The Ruins. In the uncut version available on home video, Amy is overtaken by vines at the last second. Somebody had the right idea.)