Never got into Eragon, so I can't really comment on it, but a lot of people seem to get pretty incensed over the change of Faramir and Aragorn's characters, and the larger role Arwen was given. The removal of the sacking of the Shire, the death of Saruman, the removal of Tom Bombadil, and then there was this one particular guy on these forums who was just outraged by how the movies changed the Mouth of Sauron.The_Lost_King said:Well I can understand the Lord of the Rings being different from the books. Atleast they only cut out unnecessary stuff unlike Eragon and the lightning thief.shrekfan246 said:inb4 Lord of the Rings and Harry Potter!
Though I could be misremembering these, Lemony Snicket's A Series of Unfortunate Events and the various Chronicles of Narnia films. Well, I suppose they're still something like the books... hrm... ah!
Pirates of the Caribbean. Those are based on books.
Personally, I need to read the books again, but I like the films enough to have all three extended editions and I occasionally marathon the bastards if I have enough free time (that's practically 12 hours that just gets flushed down the toilet). I think Peter Jackson and Co. did about the best they could given the source material and the time constraints they imposed on themselves while filming (considering they basically filmed all three movies back-to-back).