I think Napoleon was the one person who had the most amount of personal power. He was born poor and far from the decisive centers, but in one of the greatest revolutionary periods. Conquered many european countries, lost his power, regainit, and ruled again.
He really must had a powerfull and leading personality.
Hitler his also a good choice, it has some similarities, but in a darker version, close to mental hilness.
Julius Caesar perhaps the most admirable leading personality, who was murdered by those who didn't stand his superiority in any matter, would be my choice for his example.
I'm sad this topic has been parked, because it is very interesting.
What about Albert Einstein? His theories and work shaped the way we did everything, travel have war and even try to get to other planets.
This might seem weird but I think Adolph Hitler is the most influential. He caused war to be different. He made men use their brains to come with some of the most terrible weapons we know. Hitler made people think more about race and human worth and he killed many over it too. He involved the entire world in his plan, no one has ever caused this big a 'party'.
The Muslims' prophet Muhammed is probably the most influentional in the way his words are being interpreted by millions. There are nations built on theocracy and ideals which claim to follow his words. Their claims has led to many ongoing wars.