By skyforbes Not which were the best / worst adaptations, or which were better / worse than the book, but which were the closest / farthest from the source material.
Closest: Fear and Loathing in Las Vegas. The movie almost exactly follows the book, and many quotes from the movie are directly from the book.
Farthest: Under the Skin. The movie has the vibe of a simplistic independent horror flick that completely ignores the main theme of the book (the ethics of eating other species, since the aliens eat humans as a delicacy).
Farthest, runners up: Princess Bride and Wicked. Both movies (and play, for Wicked) leave out a ton of material from the books (almost the entire frame story for Princess Bride, Elpheba's terrorist group and journey to Fiyero's family with their son in Wicked).