When I was 10 or 11, animal stories by Sir Charles GD Roberts or stuff like Beautiful Joe, as a teenager, The Second Sex by Simone de Beauvoir, Silent Spring by Rachael Carsons and To Kill a Mockingbird.

Read a whole slew of great science fiction during that time too, such as More Than Human by Theodore Sturgeon and other classics. I thought it was more of an escape than an influence, but on second thought, it probably had a more profound affect than I realize.

Since then, I have read so many others, some better described as great literature by comparison, but the stuff I read during my childhood and youth had the most impact.