Ironically, most of the books I've been forced to read I wound up enjoying. Beowulf was tricky to read but ultimately a good epic. The Hound of the Baskervilles, Night, MacBeth, and Of Mice to Men stand out to me. (Although if you hate dark stories, stay away from Night.)
It helps that I enjoy reading and most of the bad stories I've read were almost immediately erased from memory. I honestly don't remember is I read the Scarlet Letter or not. Also I believe what books students are required to read are up to the teacher, I think, or at least it was at my school. My 12th grade class got to read Sherlock Holmes while another had to read Pride and Prejudice.
I know there was one novel we head to read that was told entirely through dialogue. And when I say that, I don't mean there was a lot of dialogue. I mean literally every sentence was dialogue. I don't remember the name of the book, but it was about a high school student who after surviving a car crash where only he (and maybe another friend) survived, which I believe was caused by drunk driving. He slowly spiraled into depression until he committed suicide. The last of the book focuses on how his friends, peers, teachers, and family reacted to his death.
I didn't like it, but if anyone remembers the name of it, let me know.