The post that was quoted here has been removedSteven Hawking if you're going scientific,
Yeats for prose
Adam Smith for economics
Jefferson for government
St. Augistine for theology (close behind is Wesley)
Churchill for world politics and leadership
Frued for Psychology (maybe Jung)
Dubois fro Sociology
Lopez for chess
Hannibal for warfare
Plato for philosophy (though I think he stole from socrates)