Depends what you mean as a 'teenager.' Are we talking thirteen and fourteen, or eighteen and nineteen? There is a huge difference. At thirteen and fourteen I was into the type of adventure stories written by Jack London. By nineteen, The Caine Mutiny. Of course I cannot list the hundreds of books I devoured with my reading over these years, but those two will give an indication of the type of fiction - and it nearly always was fiction. Non-fiction came later. And after turning thirty or so, has made up most of my reading ever since.