Using modern morality when dealing with Ancient Greece never ends well for anyone concerned. I would marginally give it to the Athenians, due to all the greatness of their philosophers, playwrights and so on, in founding Western Civilization as we know it today. That said, stripping hindsight away, the gap narrows almost to nothingness. Still very, very marginally towards the Athenians, mostly because I like them because I'm writing a fantasy story based on classical Athens/Republican Rome. (PM me for a link if you're interested, it's in fictionpress, a second chapter is fairly near completion!)
So, yes. Athens. What lovely characters I can play around with!