As for modern stuff, my focus tends to be young adult lit so I don't know much about more "adult" stuff.
A couple YA recs that I really liked and might be interesting in a classroom setting:
Challenger Deep (Neal Shusterman) (mild spoilers for the basic premise of the book because I think it's best to go into this book totally blind) - contemporary YA story about a high schooler developing mental illness - I forget the exact diagnosis but it involves profound unreality. deals heavily in how scary the world is when you can't tell what is or isn't real, and you don't know who to trust.
The Drowned Cities (Paolo Bacigalupi) - near-future story about america dissolved into anarchy, with warlords conscripting child soldiers to fight over the scraps of the world. the main characters are a couple of war orphans struggling to survive. dark and brutal, probably best suited for an older teen audience, but it also never glorifies its subject matter; one of the main themes is that soldiers themselves are also victims of war.
I love it. I'll add these to my list. I think once you get to higher grade levels it gets harder to incorporate YA lit because of curriculum requirements. At least where I live. ---
