I actually don't think I've read a 'bad' book. I may not have liked some books because it was assigned reading and a bunch of needless busy work went with it, but I don't think that's reflective of the quality of the writing.
That being said, I disliked Animal Farm & Lord of The Flies in high school, mostly for that fact, and I found that the satire & symbolism was really easy to spot, and it became kind of annoying when my teachers would obsess over & repeat the symbolic message over and over again. But the craftsmanship and writing style is very good I think. You're not supposed to like either of those books, I think. XD There's a reason why they're on pretty much every college-prep curriculum in the States.
Aside from things like Harry Potter, The Hunger Games, etc., I feel like The Lord of The Rings trilogy doesn't quite get the respect it deserves, having been the progenitor of the fantasy genre we all know and love. J.R.R Tolkein was a genius, and even to this day I have a hard time wrapping my brain around the fact that he created that entire legendarium - all of that came from his own mind. Having one of the best trio of films ever made about your books helps too.