'Stalker' – Andrei Tarkovsky

STALKER/Roadside Picnic is one for the few forms of media I know of that has been adapted into two different forms of media (movie, video game) and all three being very enjoyable.

The movie, oddly enough, is definitely more high-brow than the book (usually the opposite is the case). The game series has also, compared to other games of that era, a very different yet mainstream appeal to it.

Btw, the adaptations, both movie and game wise, are only very loosely based on the book.