I hope you like the next Robinson you try; it took me a while to get into him, but I think he's one of the most interesting and ambitious writers out there.

My favorite of his work is his atypical fantasy novella "A Short Sharp Shock," the Mars trilogy, and the Three Californias trilogy. The last offers three AUs centered around the same characters, one post-holocaust, one capitalist dystopia, and one eco-utopia. The utopia doesn't quite work, but I admire him for attempting it. It's so much easier to write about what goes wrong.