All of these are well-done, or reasonably well-done films that streamlined a source novel:
Under the Skin. The ScarJo version is creepy and nicely-filmed but has only rudimentary connections to Michel Faber's novel. A woman driving around Scotland picks up men and terrible things happen to them. In the book we clearly see, and understand, the terrible things and the politics behind them. The film's actress is a beautiful blank on whom the camera lingers for most of the run-time; Faber's "Isserley" isn't much to look at but has a rich inner life.
The Man in the High Castle. This "Amazon pilot" excels at visually conjuring Philip K. Dick's parallel world where the Germans and Japanese won World War II but dumbs it down thematically. Dick's small business and lower functionary "little people" working out their fates within the context of a larger, mostly unseen political struggle become, in the Amazon version, players in a Mel Gibsonized "French Underground" story, with calculated plot twists and Nazis beating resistors to a bloody pulp.
The Prestige. Christopher Nolan also adds Hollywood "story arc" to Christopher Priest's superb Gothic novel. The book does not hinge on an absurd murder trial, or a prisoner separated from his daughter. The steampunk element in the form of a miraculous "Tesla device" figures in both both stories, but Priest handles the revelations about its powers much more effectively.