It’s really sad when you see a movie and truly enjoy it, only later to pick up the book the film was based on, love it, and begin despising the movie version you so recently loved.
There are a few exceptions, for example, The Godfather, Roots, Goldfinger, The Andromeda Strain (orginal), One Flew Over the Cuckoo's Nest and The Color Purple. Those movies translated well to film.
Can you think of any movie adaptations you loved before you read the written version? And what was it you read that made you dislike the movie?