Lord of the Flies was probably the worst for me, followed by Red Badge of Courage. Then Of Mice and Men, then Moby Dick. I don't think the lessons I learned from those books were anything like what my teachers were expecting.
Old Man and the Sea was okay. So was Summer of my German Soldier.
I didn't have to read Catcher in the Rye or the Great Gastby, so I still haven't. I did read Animal Farm on my own, but not 1984, and I tried Fahrenheit 451 but only got a chapter or two in before I stopped.
LOVE Ender's Game, but that was never a class book. I read that about the same time I got introduced to Heinlein and Neil Gaiman.
Pan Female, Hinge in a V between my mono (straight) husband, Monochrome and my poly (pan) partner, ThatGuyInBlack