The Christian Roman Empire.
I have immense difficulty imagining you speaking Greek and wearing a himation. But I can see you kissing the Icon of the Black Madonna before battling the Persians.
To answer the (actually interesting) question -- In Roman Empire, I would likely be confined to some desert hellhole in Numidia, where the best I could hope for in life is personal slave to a Berber tribesman, who himself is a servant to the Roman proconsul.
I can imagine other scenaria (hoodrat in the native quarter of Alexandria, petty shopowner in Carthago Novo, etc.), but they are even
less appealing than slavery.
I'd take 21st century America (hell, even 19th century America) over Rome, TYVM.