no particular order, these come to mind:

-- Thus Spoke Zarathustra, Friedrich Nietzsche
-- Meditations, Marcus Aurelius
-- A Brief History of Time, Stephen Hawking

Honorable mentions
-- Walden, Henry David Thoreau
-- Beyond Good and Evil, Friedrich Nietzsche
-- Atlas Shrugged, Ayn Rand
-- 1984, George Orwell

And of course
-- Super System, Doyle Brunson
-- Theory of Poker, David Sklansky