I'll give a few suggestions to get us rollin.

Industrial Society And Its Future - Ted Kaczynski

This is the book I'd want to read and discuss with intelligent independent thinkers. I think this book has some very important critiques of modern society that would lead to some great discussions. Kinda heavy material, but it isn't that long, I'll keep the rest of my suggestions lighter

I'll suggest a few classic literature pieces

Crime And Punishment - Fyodor Dostoevsky

Originally suggested by FuckYourMom, Great classic novel, there is societal commentary and some serious evaluations of morality. I've read this (a long time ago) and it is a very good suggestion.

A Brave New World -Aldous Huxley

This seems like it would be up Saiditors alley. It's very similar to Orwell's 1984, but predates it. I assume many are like me have read 1984 already, but not this one.

And a sci-fi suggestion

Lord of Light - Roger Zelazny

I haven't read this either, but its been on my list for a while. Sci-fi work similar to Dune, written around the same time. The movie Argo, where the CIA makes a fake movie, the fake movie is about this novel. Its a novel about rebelling against powerful and corrupt authorities.