Ooh, Julie of the Wolves! I loved that book. My sister had it, but it seemed like she never read it, so I just kind of...acquired it, heh. Also Island of the Blue Dolphins, which is similar. I read a ton of horse books as a kid, too, and the Laura Ingalls books and of course A Little Princess and The Secret Garden. 'The Horse and His Boy' was my favorite of the Narnia books.

All time favorite as a kid? The Changling, by Zilpha Keatly Snyder. She wrote such wonderful stories!!

I think 'best book ever' is hard - there are so many! Brideshead Revisited, Out of Africa, Flame Trees of Thika, The Flambards, The Jungle Books, Watership Down...pretty much ever Cherryh and Tanith Lee book ever.... Let's just say if I still own it, it was good! :D