Since you're a teacher, you're going to get things I simply won't.
Back to "Catcher in the Rye" I first read it when I was somewhere in my twenties, in the 1970's, and I actually liked it a lot, even though it portrayed a world that was already long dead by then. To be honest, my enjoyment of the book was in no small part because I thought I understood that world, even though I'd never been a part of it.
I believe Salinger was very much a part of the world that Holden Caulfield inhabits: the world or private schools and privilege. A world hugely separated from ordinary public schools. Perhaps because my kids started out in public schools, and only wound up in a private school for very specific reasons, and not because we were of the class of people who of course sent our kids to private schools, that I recognize the gulf between Holden Caulfield's world and mine. Which is to say, between J D Salinger's world and mine.
I like it that you say you have books in your curriculum but they aren't required. How do you deal with the kids who don't want to read a specific book in the curriculum? How free a choice do they have? That's not intended as a gotcha question, but an genuine inquiry as to how you handle such things. And, do you care about catching out the kids who only read the Cliff Notes?
The more fundamental point of what's worth reading would require a lengthy face to face conversation, hopefully with plenty of wine to fuel the conversation. I have taken various literature courses in junior college, and since I was an older student at that point, I tended to enjoy the required reading much more than I would have at a younger age. I've also had the pleasure of reading, on my own, various books that are often required reading, and enjoyed them tremendously. The best example here is that some years ago, when Talk of the Nation had its bookclub on the air, and one of the books chosen was "Uncle Tom's Cabin" I decided to read it. I figured it would be a slog, but it was one of those classics that I knew I should read. Well, for me the first fifty pages were a bit of a slog, but after that it picked up, and I simply could not put the book down. One of the best things I've ever read. Better yet, I got to be one of the on-air participants in the first half hour of the discussion, which is still one of the high points of my life.
It is certainly possible that had my son picked up "Catcher in the Rye" on his own he'd have loved it, and it was the required reading aspect that spoiled it for him. Alas, there's no way of knowing.
Again, thank you for your thoughtful response to my post.