Um, maybe Ralph Bakshi movie is an atrocity for you. For me it's the best Tolkien adaptation ever.
That rotoscoped steaming turd? I've rarely been more disappointed at a movie. It had reasonable fidelity to the books but that alone was hardly enough to make it good. I remember excitedly renting it from the video store sometime during the 1980s and thought that it was a really badly done movie. I thought the rotoscoping was bizarre and still do - uncanny valley reaction I guess. The voice acting was meh at best and the "action" was nothing to write home to mom about. Plus they released it as The Lord of The Rings but it only covered about half the story. I can live with it being condensed into a single movie even if they chop a lot out but then give some indication that there is more to the story. I clearly remember saying "That's it? Where is the rest of it?"
Jackson's adaptations of LOTR, like the recent The Hobbit trilogy, could have used more editing but it was at least in general a good and engaging movie. Visually excellent, faithful enough to the books in most places, captures the epic The worst bits of Jackson's adaptations are when they start going off script for stupid jokes like the dwarf tossing joke during the battle of helm's deep. It wasn't all bad but a high percentage of the dialog that deviated from Tolkien's words was pretty campy. That sort of thing should have only been on a gag reel. More editing would could have made a tighter story but it was a decent movie even if an imperfect adaptation.