Voltaire.

Camus, Popper, Habermas, Hume, WD Ross, Abu al-Alaa al-Maarri, Dennett…

Definitely NOT Ayn Rand

None of those. My top is Jean Paul Sartre.

Hello and welcome to the site.

If I may though I would say that I think that, Socrates and Plato are in many ways just about the same one, there are few surviving Socratic ideas which do not come through Plato, ( A few poor quality ones from Xenophon and one or two others, but not many. ) I think that Aristotle would have been a better alternative, and would have got my vote.