Every major thinker from stoicism

Go read the most hated feminist ever(hated by feminists): Esther Vilar. Don't read what feminists write about her, just read what she wrote. It's probably the most dangerous writing to have ever come from a woman and the feminists. Keep in mind she was an M.D. Her books aren't that long. Maybe an afternoon read for each and the third hasn't been translated into English. They are "The manipulated man" and "The polygamous sex". She hit the nail on the head.

Next up on the roster, if you want current stuff, is Rollo.He just made a historic observation of the "kill to party" phenomenon with Mikhaila Peterson and also the loss of emotional control by Jack Murphy. I mean the guy is hitting the ball out of the park on a regular basis.

Chris Rock, bar none. It's pretty much how I knew about Red Pill before it was even a thing. I was pretty red pilled by the time I found the communities.

Ayn Rand is the genius of the ages. Her philosophy of Objectivism is the greater intellectual framework that something true, but heterodox like TRP fits into.

Venkatesh Rao. Nassim Nicholas Taleb. Ayn Rand.

Friedrich Nietzsche has been considered red-pilled by many

The oldest Red Pill text I have found is the Bhagavad Gita:

Bhagavad Gita 1.41-1.44 With the preponderance of vice, O Krishna, the women of the family become immoral; and from the immorality of women, O descendent of Vrishni, unwanted progeny are born. (The lament of the singe mom, I didn't want to give birth, it just happened) An increase in unwanted children results in hellish life both for the family and for those who destroy the family. Deprived of sacrificial offerings, the ancestors of such corrupt families also fall. (sacrificial offerings? voodoo bullshit! proceed to dismiss the entirety of the text, get drunk, hook up and become a single mom) Through the evil deeds of those who destroy the family tradition and thus give rise to unwanted progeny, a variety of social and family welfare activities are ruined. (Women are more haaaappy and independent than ever, right?) O Janardan (Krishna), I have heard from the learned that those who destroy family traditions dwell in hell for an indefinite period of time. (In Hinduism, hell is not really eternal, it's just a really long time until rebirth, the highest form of punishment for the most heinous crime of destroying the family is indefinite-y in hell)

https://www.holy-bhagavad-gita.org/chapter/1