There’s a big difference between books that shouldn’t be adapted into films and books that couldn’t be adapted into films. Books that shouldn’t be are generally subjective and frequently the subject of drunken tirades (e.g. “No, but I, like, am Oscar de Leon; I would boycott all movies ever if they adapted The Brief Wondrous Life of Oscar Wao!”). Books that couldn’t be adapted, on the other hand, have reasons for never seeing the silver screen that are logical and not completely emotional. Either the author would never allow it or audiences wouldn't "get it" or the translation from page to screen would be technically impossible.

Some of the 10 books below fall into the "shouldn't" category and some into the "couldn't" category. Regardless, they won’t ever be coming to a theater near you.