People positively love bitching about how an optioned book butchers the original printed story, but rarely do we see anyone comment on the reverse.
Yesterday, I was doing a search for this exact thing but many of my searches were returned with names like Fight Club (where the ending is completely changed), Brokeback Mountain (which was expanded substantially off the 13 page story), and One Flew Over the Cuckoo's Nest.
So, being sure that people just picked book-based cinema they liked, I've made my own list.
Everything here keeps closely to the story, tone, and themes of their original ink inscribed counterparts.
5. A Clockwork Orange
A know that people will disagree, but we must bare in mind that Kubrick's version was done off the American version of the novel, the one missing the final chapter that rejects senseless violence. With that in mind, the tone of dystopian society swathed in violence from the state and the citizens is well kept, and the dialogue is nearly word for word.
4. Harry Potter and the Philosopher's/Sorcerers Stone
Back before it donned on Warner Brothers that the could slap 'Harry Potter' on any movie trailer and the fans would show up regardless of quality, they cared about those books its started as and for two movies did a goddamn job of adaptation.
3. Running With Scissors
Ryan Murphy manages to do something exceptionally rare for a film based on memoirs and that's to not fuse a bunch of characters into one.
2. No Country For Old Men
I don't know how many times I can rephrase 'well translated tone' and 'original dialogue but the film version has both.
1. A Scanner Darkly
Written during Philip K. Dick's prolific explosion of science fiction novels, not only is the tone, every motif, and the exact dialogue translated perfectly to the silver screen, its almost improved by the disjointed soundtrack and use of interpolated rotoscope animation.