I can also see the works of Arthur Schopenhauer being of great interest to many HN readers. His reconciliation of Western philosophy (especially Kant and British Empiricists) with Buddhism and Hinduism is unique and for me the most interesting overall system. His work is entirely worth reading for the quality of writing alone. For me, his works evoke the experience of mathematical beauty. I would recommend gaining a basic understanding of Kant, Buddhism, Hinduism, and then reading his work "Essays and Aphorisms," followed by "The World as Will and Idea."
"Propaganda: The Formation of Men's Attitudes" by Jacques Ellul is the book I have read that best explains the human experience in the modern media environment. Like "The World as Will and Representation," it also forms a sort of complete system, which can be read as an organic whole as well as with self-referential parts. I believe most of the "alienation" we experience from technology, which is often blamed on the internet, is really a much older and broader phenomenon, which Ellul attributes to the development of the radio, "technique," and broader phenomenological experience within 20th-century totalitarian societies.
"Simulacra and Simulation" is another that I have enjoyed. It is the work I have read that, in my opinion, best provides a model for living in a post-modern, post-industrial society, and my intuition is that it will also prove authentic in the age of artificial intelligence.