I would say that any true American, whether you've heard of him or not, would be in the top five.
The person who gets up every morning, puts on his steel-toe boots, or puts on her apron is one of the top five figures in America.
Americans make this country. Leaders come and go, they get voted in, or out, they die with time, but the spirit that made America great is not in those people. It is in the ones who do the right thing without thinking about it. They are the people who work hard for the money that is taken through taxes or other promised entitlement fees.
Men and women across this great country are in the top five figures of American History. The men with their rifles in WWII, and the women with power drills in their hands are in that top five.
Celebrity, money, and political prowess do not make a person top of the heap in America. The entire population of this country--those who love her, protect her, serve the needs of her, and think about the future of her are in the top five.
The soldier in the sand heap, or in the muddy bog are at the top of the list. The mother who cares for the children who may never see their father is at the top of the list. The elderly mothers who sent their children off to fight the good fight to keep her country safe is in the top five. The man with one leg and burned skin from an explosive device on the side of the road is in the top five.
The unnamed American should be the top of any list. No leader can lead unless given the opportunity by those Americans who put him/her there.