I'd have to say Ron Paul. Ron Paul in my mind spoke the truth and practiced it. He opened my mind to other possibilities and helped me understand the world we live in better, with solutions to problems.
He has encouraged me to look into our past. By looking in the past I can see our future. The past usually repeats itself, and we never learn from our mistakes, we forget our mistakes.
Other great people, Thomas Jefferson, Plato, Socrates, Gandhi, Peter Schiff, Jacque Fresco, a bunch of Austrian economists. The list can go on and on.