I think all the books still lend themselves a lot better to animation than feature films. I like The Fellowship of the Ring though, the rest of the films, not so much.
I have issues with how a lot of things look, like Gimli, he doesen't look very tough beneath all that rubber foam makup. The physics look wrong. Sticking hair on a guys feet and shrinking him doesen't make him look like a hobbit, neither do elves with 5 o clock shadows inspire that much.
Although the goblins in Moria were spot on to me, Frodo was ok as well somehow, maybe because of the baby looks of Elijah Wood.
They did an animation of LotR already, which is not worth watching 2 seconds of, with the exception of the design of the Nazgul, quite awesome.