I particularly enjoyed his novel, "Smack". But also some others for those of you that are into that type of thing: -"Go Ask Alice" -"Trainspotting" Not by the same author, but still, good stuff.
I really like his books too. They are have such vastly diffrent themes. The thing that impressed me most about Smack was have so many distinct narrative voices. So you got the complete picture and understood all the characters. Got a copy of Trainspotting a while ago, keep meaning to read that. BTW In the UK 'Smack' is entitled 'Junk' (another term for heroin that apparently we're more familiar with. Got confused by that myself)