As everybody and Tom Bombadil knows, The Hobbit trilogy is not going to follow the books as faithfully as we might have hoped, with an extra elf character and much more screen time than pages in the book. But we're keeping up hope that it will still be fantastic, and you should too! After all, these movie adaptations didn't follow the books and they were still fantastic:
Film: The Chronicles of Narnia: Prince Caspian (2008)
Book: Prince Caspian: The Return to Narnia (1951)
What They Changed: Plot and characterization. There's ill will between Prince Caspian and Peter, when they got along just dandy in the book. Also, the whole attack on King Miraz's castle sequence was added in. Other minor things were changed, like when the Pevensies meet up with Caspian's army and what happens after the battle, but these were the two most major things.
Why They Changed: The screenwriters and the director had a hard time turning Prince Caspian into a compelling movie, as it's often called the weakest of the series. The book only had one battle and there's little intra-character conflict, so the makers wanted to add more action and tension.
Why It's Great: We speak from a true love of the books, so don't skewer us when we say this: Prince Caspian isn't the most compelling book. There's little to no character development in any of the Pevensies, who also disappear for half the book during a large flashback sequence. The film is one of those few movies that we could say is better than the book.
Film: V for Vendetta (2005)
Comic: V for Vendetta (1982-1989)
What They Changed: Close to everything. Instead of Parliament being blown up at the beginning, it's blown up at the end. V kills Lewis Prothero instead of making him crazy, V was killed by Creedy and his men, not Finch, the Head was killed by Creedy, not Almond's wife (who didn't even exist in the movie), along with many other characters who either didn't exist or whose names were changed. Biggest of all, Evey didn't become the next V in the film, everybody did. Or something.
Why They Changed: The Wachowski brothers wanted to modernize the story and make it more universal and less vague.
Why It's Great: V for Vendetta is not a good adaptation of the comic, but it is still a great movie. Mostly because V is in it. Hugo Weaving did an immaculate job as the anarchist hero and stayed almost completely faithful to the book's V. Even if there was that one kooky scene with him fighting a suit of armor.
Film: The Count of Monte Cristo (2002)
Book: Le Comte de Monte-Cristo (1844-1845)
What They Changed: So much that listing it all here would take too much bandwidth. The movie cut out more than half the main characters and changed much of the plot.
Why They Changed: The book is a monster, and it didn't have as much action as a movie is generally expected to have.
Why It's Great: The movie, while not following the book, was full of great acting, fantastic sword fighting scenes, and a great plot.
Film: Lord of the Rings: The Fellowship of the Ring (2001)
Book: The Fellowship of the Ring (1954)
What They Changed: Mainly plot and timing. Instead of letting the reader learn the One Ring's history along with Frodo like in the book, Jackson condensed the history into a prologue where Sauron beats up on the Free Peoples, among other things. And you know that period between when Gandalf leaves the Shire to investigate the Ring and when he comes back? In the book that was 17 years. Tom Bombadil and the Barrow Wights are left out, and instead of the elf Glorfindel coming to help Aragorn and Frodo, it's Aragorn's love Arwen.
Why They Changed: Jackson really wanted his film to focus on Frodo and the Ring, which he considered the backbone of the story. We have to admit that in the book, the first 90 pages are a bit of a drag, and we love Tolkien.
Why It's Great: The film still stays very true to Tolkien's heart, and explores nuances of the plot that true Tolkien lovers really want to know more about, such as Arwen and Aragorn's love thing.
Film: The Shining (1980)
Book: The Shining (1977)
What They Changed: Besides the differences in events (Dick Hallorann dies in the movie, etc.), the movie is much different from the book in that it's a psychological horror, not a supernatural horror. If you read the back of the DVD case it'll say Jack succumbs to "cabin fever." It's Jack's fault he wants to kill his family; the supernatural power of the hotel just gave him a nudge.
Why They Changed: It's kind of hard to say why Kubrick did anything, but Kubrick wanted his film to be more existential, so he focused more on suspense than on some unknown demonic entity.
Why It's Great: The film is full of suspense, replete with scenes whose score builds to what seems like is going to be a horrific climax but turns out to be a black screen saying "One month later." Kubrick also got you to feel how alone the family is in the gigantic hotel, and want anything but to see what's in Room 217.