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 the Hughes Brothers' adaptation of Alan Moore's From Hell, read on...
Name: Mary Kelly
Fate: Survived the Jack the Ripper murders, despite her being the prettiest of all the dirty whores.
Verdict: I would've killed her. Because that's the way it actually happened.
Reason: From Hell, the film, cuts a lot of corners with Alan Moore's exhaustive comic book expose on Jack the Ripper. It tries to turn a character study into a whodunit, it gives Inspector Abberline a series of psychic visions as a lazy way of getting from Point A to Point B in the plot, and strangely, it leaves Mary Kelly alive while killing Abberline, exactly the opposite of what occurred in real life.
When Heather Graham's prostitute character was kept alive in the Hughes Brothers' film, I assumed it was to provide a tidy studio-style romance coda to a grim thriller -- of course the two attractive leads get to make goo-goo eyes at each other as the credits roll. Imagine my surprise then when they killed Inspector Abberline in an opium den. Didn't see that coming.
What purpose did it serve to keep Mary Kelly alive, exactly? Moore does it as well, by making Mary a victim of mistaken identity, but he provides a terrific pay-off for the switcharoo -- the haunting image of the Ripper calling out from Hell while Kelly ignores him.