Example; the Legend of Zelda: BotW and TotK weapon degradation system. At first I was annoyed at it, but once I stopped caring about my “favorite weapon” I really started to enjoy the system. I think it lends really well to the sandbox nature of the game and it itches that resourcefulness nature inside me.
I would probably say that FOTR is my least favourite of the LOTR trilogy, TTT and ROTK are both more enjoyable IMO.
That said, I saw the movies before I read the books, so that might be a factor, I’m not sure.
Personally, my favorite book of his is the Silmarillion, he’s in his element and is writing a text book about cool fantasy stuff he dreamt up.