Well, here's what YA Guy was (and is) reading (and though biologically I've grown up, I still read the same things I read in my YA years!).
Note: this list is in no particular order. Everything on it is guaranteed, bona fide great!
1. J. R. R. Tolkien, The Lord of the Rings. Not technically YA, as the category didn't exist in Tolkien's time, but close enough!
2. James Dashner, The Maze Runner. And its sequel, The Scorch Trials.
3. Roland Smith, Peak. Wonderful storyteller, great economy of voice.
4. Chris Howard, Rootless. Amazing dystopian novel about a world without trees. Sequels forthcoming.
5. J. Barton Mitchell, Midnight City. Totally creepy alien-invasion novel. Beware the Tone!
6. Suzanne Collins, The Hunger Games. Just plain a great book, for boys and girls. The sequels rock too.
7. Mark Twain, The Adventures of Huckleberry Finn. Still one of the greatest boy books--scratch that, books--of all time.
8. John Green, The Fault in Our Stars. Female narrator, but so what? This is Green's best book--and that's saying something.
9. M. T. Anderson, Feed. A world hooked on the internet. Wait, is that the future?
10. S. E. Hinton, The Outsiders. Hinton initialed her name so no one would know she was a woman. But her book remains one of the all-time great boy books.
So there you have it. If I'd allowed myself fifteen or twenty or a hundred, I could have gone on and on. What would you add to the list?