Well, its a tie between Ghenghis Khan, who, simply put, owns, and Marcus Aurelius, becouse I find a man who can slaughter the german tribes and then sit on the riverbed and philosophise about the greatness and inherent meaninglessness of life a very, very interesting personality.
Close seconds are Buddha, simply for finding a completely new and in some ways still riddled approach to life, and Canute the Great, who gets a lot of negative points in my book for semi-converting.
Third ones would be Louis The Great of Hungary, for taking over a quite out-of-shape country, and battering it into a b*tch stretching from sea to sea, and Mohamed.
Golden Lion award goes to Gustav Adolph II, and his house occultist, Johannes Bureus (I guess you are all schocked now, aye?)
Ouroboros award goes to Jaques "my do curses work" de Molay.