Nit-Pickers Guide to Deviations in Jackson's LotR
bcolflesh submits "A lengthy list of deviations to be found when comparing the text of The Lord of the Rings by J.R.R. Tolkien and the translation of those texts to film as undertaken by Peter Jackson, et.al."
Agreed. I might add one more thing: Sam turning around in Mordor in ROTK. Not only was this not in the book, but it is a complete reversal in the character developed so well in the movies themselves. I do not feel that it is true to Sam's character in the least. If you are going to have a rift between Frodo and Sam, at least have Sam wait for a bit and then follow from a distance.
Imagine this scene if you will. Frodo tells Sam to leave and continues up the stair. Sam sits down and cries. He finally gets up and starts to look down the stairs. He stiffens and mutters, "I made a promise." He then sets his shoulders and begins the climb up the stairs. You still have the rift, but at least Sam stays true to himself. While this is certainly not from the book, it would at least lend consistency within the movies.
I believe in de-evolution. God made the world perfect, man fell, and its been going downhill ever since!