When I was young I devoured series. Encyclopedia Brown books, Nancy Drew books, Hardy Boys, The Black Stallion series. the Marguerite Henry horse books...then I found Dragonlance and I was hooked.
I also recall a large size picture book of the black stallion, with fabulous drawings inside.
So, I guess if I were going to gift a book of my past to a kid today, it would depend on the kid. Mystery, animals, or fantasy... To me, so long as they read something they find interesting, it doesn't much matter what.