I think the young adult books that spoke to you when you were 11 and pre-pubescent (awful word; we now call it tween, which is possibly more awful) form your adult tastes. For me it was Madeline L’ Engle’s A Wrinkle In Time with a side of Walter Farley’s The Black Stallion. It was a direct path from here into fantasy, sci-fi, adventure stories and animals.
Give me some Call It Courage about a cannibal island or Farley Mowat’s Never Cry Wolf. Also The Yearling. A Separate Peace. Charlotte’s Web. The Phantom Tollbooth. And now I’m re-reading these things.
Why do this, when there are so much great new books to discover? 1) I have kids and they are just getting into the American Y.A. canon, and 2) I believe T.S. Eliot when he said in Little Gidding (which I learned is a place, and not as I had thought, a little girl), “We shall not cease from exploration/ And the end of all our exploring/ Will be to arrive where we started/ And know the place for the first time.”