Philosophical Speculations

I encountered Pelevin just about 7-8 months ago, and since then I read everything from him I could get my hand on. Practically all of his books involve metaphysics as a central plot element, and these tend to be pretty hardcore idealist concepts. Pelevin is a self-professed Buddhist, and he's clearly also very interested in mysticism, both of which leave their mark on his books. He also has first-class prose and writes very entertainingly, with a characteristic dry humour.
For a first read I'd highly recommend iPhuck10, Secret Views of Mount Fuji, and the latest one, The Invincible Sun.
Word of warning: existential angst guaranteed.