Simulacra and Simulation. He passionately and humorously cuts the Faustian worldview to ribbons. Extremely eye opening and refreshing, it essentially explicates the limits and catastropic end of the 'modern', Hegelian, socialist Weltanschauung, and suggests what might be next.
In my opinion it ties in very nicely and pairs well as the germ of answer to the question revealed by Oswald Spengler's Decline of the West, which I'm gradually in the process of going through: "What's next?"