For philosophical sci-fi The Left Hand of Darkness and The Dispossessed by Ursula K Le Guin and Parable of the Sower by Octavia E Butler are all amazing. I just read The Origins of Totalitarianism by Hannah Arendt which is quite dense but also good and felt very relevant to current times. I'm planning on reading Eichmann in Jerusalem next, which is about the banality of evil.