IMHO, the books were good, the first movie was disappointing, and the second movie was an improvement. I'll watch Eclipse, but I'll wait for it to come out on DVD because I hate going to the theaters.
The problem with this series in film is that they keep screwing with the story too much. They add stuff to the movies that didn't happen in the books and they omit stuff from the movies that would have been good scenes. I understand that things have to get shuffled around a bit when translating a book to a movie, but I think they messed with they messed with this story a lot more than necessary.