Well I don't think you get much more die hard Tolkien fan than Christopher Tolkien.

Invited to meet Peter Jackson, the Tolkien family preferred not to. Why? "They eviscerated the book by making it an action movie for young people aged 15 to 25," Christopher says regretfully. "And it seems that The Hobbit will be the same kind of film."

This divorce has been systematically driven by the logic of Hollywood. "Tolkien has become a monster, devoured by his own popularity and absorbed into the absurdity of our time," Christopher Tolkien observes sadly. "The chasm between the beauty and seriousness of the work, and what it has become, has overwhelmed me. The commercialization has reduced the aesthetic and philosophical impact of the creation to nothing. There is only one solution for me: to turn my head away."

My Father's "Eviscerated" Work - Son Of Hobbit Scribe J.R.R. Tolkien Finally Speaks Out

There he's talking about all the films, the LOR as well as the Hobbit.

I'm not sure if this question is about the LOR trilogy or the Hobbit trilogy.

I'm keen on the novels myself also, but haven't yet managed to watch one of the movies all the way through. Though - that is watching them at home where I can skip bits that don't interest me - and so I do just that.

With the LOR - well the sets were good, some of the acting was good - but I was disappointed that they left out the best bits (for me) and seem to have lost the plot as regards what I see as the core messages.

As Christopher Tolkein said - the beauty, and seriousness, I'd say also, sense of depth and history and unexpected sidelights. Also - light hearted aspects. I think it was a big mistake to leave out Tom Bombadil as the only person who was not affected by the ring in any way. Perhaps he didn't "get him" but if so, that suggests missing the point of the whole book, it's not just a fight between evil and good, it's got this other dimension also that it's just one small incident in the vast history of middle Earth and there are some who are totally unaffected by the ring - so it loses a lot of the depth and breadth of the story to leave him out as the only character in the book who has that perspective. It just gets far too black and white, and unavoidably "heavy" if every character in the book is totally bound up with the ring.

Also in the original nearly all the characters sing on almost every opportunity - a reflection back to an earlier world when people were more light hearted perhaps and certainly sung while they worked, and sung a lot more (according to reports of song collectors in late C19 Britain for instance).

But I've not watched them for some time and only watched parts of the LOR, and don't have it on DVD.

See comments for my previous answer about the Hobbit, when I thought the question was also about the Hobbit trilogy.

And - some day I'll maybe have another try at watching the films. :). You can always say, maybe it was just a bad day, maybe on another occasion I'll "get" them, what the movies are all about, what Peter Jackson's overall vision was, and find the vision he presents more immersive.

But give me the book over the film any time.

I look forward to whenever the films go out of copyright, if they do, maybe then we'll get some good independent fan films of the LOR, perhaps in 2044? (By which time I'll be 90).

And it seems very much a lost opportunity. They could have made so much more of it. Surely they could have satisfied both types of viewer to some extent?

When will copyright restrictions expire on The Lord of the Rings?

See also What is the most pernicious and persistent myth about The Lord of the Rings that is believed by people who have seen Peter Jackson's movies but haven't read the books?

for some of the issues fans of Tolkien's books have with the movies.

And for a list of misconceptions about the Lord of the Rings, including many that are propogated in the movie, see Misconceptions - Tolkien Gateway