On the subject of novels being rendered as movies, that's always (or at least usually) tough to do.
But one POSITIVE example I immediately thought of was Cider House Rules, a wonderful novel, and a wonderful movie.
Why? Because the author of the novel (whose name I've culpably forgotten for the moment) would sell the film rights to the novel only on the condition that he, personally, had to write the film script; otherwise, forget it, there would be no movie.
I heard him interviewed on NPR. He said he had no objection, in general, to his novels being turned into films by other writers, and that several of his prior novels had indeed been successfully converted to film by others, but from the time he started writing Cider House Rules he was rock-solid set on writing the film script for this one himself.
And a masterful job he did on it, indeed. See it, if you haven't.