The worst for me was George Orwell’s 1984. The foreshadowing for contnual depression was just too much.
Like @jeffgoldblumsprivatefacilities the Brothers Karamazov was another non finisher. In fact, it was almost a non starter.
Although I didn’t hate Brave New World as much as @Vannessuh, I cheated on it and skimmed through the last half.
I did like the Hobbit, though, which some other posters had trouble with. I think the problem a lot of people have with it is that they expect it to be a big impressive epic kind of story, like the Lord of the Rings trilogy which follows. Most people have forgotten that the author J.R.R. Tolkien, wrote the Hobbit for his children, when they were just kids. It’s a children’s book and a rather lightweight, juvenile story. He then went on to write the Lord of the Rings trilogy from a completely different, adult point of view. The books are part of the same storyline, but almost separate genres.
As for the Fellowship of the Ring – the first volume of the Lord of the Rings – which the OP had trouble with, I liked that and the two volumes which follow. In fact, I’ve read them all twice. Personally, I think that the writing is great, although the style reflects the more leisurely, thoughtful way of writing and reading of the era when Tokien authored it. I don’t know how old the OP is, but I can see why young people today have trouble with it.