Marcus? Wrote in Greek. Maybe Plotin. What else?
In terms of philosophers alone, I suppose only Cicero or Seneca would spring to mind, and Seneca in particular followed closely in Epicurus' footsteps (I think, it's been a long long time, please correct if wrong).
These are just people who I am aware are widely read today, I can say nothing for their barbarity or otherwise. I don't know anything about Plotinus, for example, and I don't even know which Marcus you refer to, so I am hardly a very reliable source.
Philosophers are rather beside the point though: for every famous philosopher, ancient Greece had a million farmers, merchants, seafarers and slaves. I'm not persuaded medieval Britain was more enlightened than modern Britain because Shakespeare was a more insightful commentator on the human condition than JK Rowling, and the same applies to not unduly revering the societies of classical antiquity because some of the works of their educated elites have survived to the present day.