Who was the best?

I vote Joan of Arc

I wouldn't call Joan of Arc 'ancient', although if the tales of her are true, she can be considerered a great leader.

If she can count and by 'ancient' we mean the middle ages and before then i'd be tempted to say Mehmet 'Fatih' II, conquerer of Constantinople, Saladin - the honourable leader of the Saracens who expelled the Christian crusades. And finally Ghengis Kahn for just being a ruthless bloodthirsty womaniser :-P