I thought the goblins/orcs/whatever looked a little shitty, even compared to LOTR.
I can't even remember most of the films, or the book for that matter... but I remember the book had more of a magical feeling to it. Really lighthearted, even when scary shit was happening. And I didn't like how they did mirkwood - in fact, I can barely remember it. When I try to think back to that scene I imagine it as I pictured in my head when reading the book.
Idk though, there's just.. something missing from the movies. I still enjoyed them though, and I'll surely watch them a few more times.

The only problem I had with the movies were the way the orcs looked. Not a fan of the CGI.

Other than that, in glad the movie isn't a carbon copy of the book.