I've heard a lot of horror stories about some of the books people were forced to read in school - I know my Dad certainly wasn't impressed by the selection his school offered - but I was very lucky in that the majority of the books I was given to read during school I really enjoyed. In fact I got to read everything from Macbeth to Skellig to Jane Eyre; it wasn't until I got to A Level English Literature that I was given assigned texts to read that I didn't enjoy.
It was during my GCSEs I had to read Steinbeck's Of Mice and Men. It was my first (and so far only) foray into Steinbeck's work, and also my first experience with American Literature. I'd be a liar if I said I read this book and instantly loved it, but I certainly didn't dislike it. What I've found about this book, in my experience, is that it needs time to sit in your brain and slowly worm its way into your thoughts.
I don't know if I'd say this was my favourite of the books I had to read in school, but it's definitely the classic I've thought about the most; I had to read this book almost eight years ago now, and I think it says something that it's a story I still think about even now.
I haven't had much luck with American Literature: during my A Levels I had to read both The Great Gatsby and Death of a Salesman and I'm sorry to say I despised them both. Steinbeck is the first American author who really made me think long and hard about 'The American Dream' and what it means, and as a writer I'm certain this book encouraged my interest in justice and whether or not a character deserves the comeuppance they receive.