I don't know how anyone could say that Napoleon was an overrated historical figure given his impact. Same with Hitler, who was a monster, yet we are living with the consequences of his actions to this day—and will forevermore.
My picks would be: MLK, Nelson Mandela, and Gorbachev. I wouldn't even put Hillary in this group as she's not a historical figure and I don't think she'll ever be elected POTUS.