China Mieville is about the weirdest that I really enjoyed reading, so +1 for him.
Slightly lower on my enjoyment scale would be Deus Irae by Dick & Zelazny, two true titans of SF. Somehow their collaboration was just too... weird.
Also Robert Anton Wilson's 'Schrodinger's Cat' trilogy. I think my brain just isn't big enough for him.
Things I suffered through for school, like Joyce, are mostly repressed memories now.
