Here is an interesting chart comparing the book and the movie (and also the second movie):
http://en.m.wikipedia.org/wiki/User
aul2387/Differences_between_book_and_film_versions_of_Charlie_and_the_Chocolate_Factory
Sometimes I feel like the only one who doesn't think of the movie first when thinking of the story. Having read the book first, several differences, such as Veruca's downfall, kind of take me a while to remember from the movie. Especially something like Grandpa Joe, who IMO was not "bad" at all in the book, I would have never thought about any reason to hate him in the movie.
Despite reading the book first, and despite Dahl's shunning of the movie, I still love the movie almost as much as the book (as opposed to, say, The Wizard of Oz, where I just ended up really disappointed with the movie compared to the book upon first watch).