I would have to say the U.S Pres. Kennedy. (Because I am in the U S). If he didn't decide to put up a convoy block in Cuba and went and attacked, we would have had a Nuke exchange with Cuba, Russia.
I personally HATE political things, but he was one of the 'greats'. Another is Mr. Babbage (Computer Creator?)
Without him, no pc's = no internet = no forum
And M. Luther king, Mickey Mantle (Met him once in 1980), and the 'real' Braveheart guy. William Wallace. And more.. just can't think right now.
Ziroc