For starters this list does not include fundamental of specific major religions, such as the Christian Bible or Muslim Qur'an. There are many entire websites devoted to studies of these books and their influence is obvious. The books listed here are by diverse classic and contemporary authors that you find quoted in blogs, online magazines, eBooks and social networks like Facebook or reading websites like Goodreads and Bookish. They make people laugh, think or sometimes even get off their butts and do something for somebody beside themselves.
http://www.ranker.com/list/25-books-frequently-quoted-on-the-internet-v2/konnoisseur411, books, authors, books, writers,
Harry Potter and the Deathly Hallows
Oh, the Places You'll Go!
Quote from the book: "You have brains in your head. You have feet in your shoes. You can steer yourself in any direction you choose. You're on your own."
The Fellowship of the Ring
The Alchemist
Letter to My Daughter
The World As I See It
A Testament of Hope : The Essential Writings and Speeches of Martin Luther King, Jr.
The River of Winged Dreams
Just Kids
Divergent
Quote from book: "We believe in ordinary acts of bravery, the courage that drives one person to stand up for another."