I've read LOADS of books that have impressed me. I don't know if any of them have changed my life, but they've made great escapes.
One book I read a few years ago that I believe EVERY high school student should read is Gary Jennings' "Aztec Blood". It is essentially the history of Mexico, condensed into one man's life story, which takes place in the early 1600s. I was working night shift in a nursing home when I picked up the book in a pile someone had discarded. What a treasure! Someone had written notes all through the book, about all the pyramids and various sites she had visited!
My brother has a book that changed his life; he read it as a junior in high school. It is "The Fountainhead" by Ayn Rand. It gave him the drive to succeed in college, and he is now a cardiologist.
Ayn Rand wound up becoming his favorite author. Unfortunately, I may have ruined that by giving him the movie, "The Passion of Ayn Rand" as a birthday gift. The woman had few scruples! However, I don't see why he should hold that against her; everyone has faults...