Well, I saw the movie before I read the book... So I didn't really have any expectations..
But when I read the book I was very amused by the scene where Edward holds back all the cars at the school's packing lot so that Eric (I think... or was it Mike or Tyler?) could ask Bella to the dance... Because he wanted to laugh at her response... It's a shame that scene didn't make it to the big screen. It could have been pretty funny

Other than that I also liked the scene in Carlisle's office, where Edward tells Bella about the family history etc. It could have been interesting too in the movie.
But I do see that it would be impossible to include everything. The movie is already pretty long compared to similar movies