Filth is amazing. Maribou Stork Nightmares is excellent too - that one will stick with you, mark my words. Glue is about another bunch of lads from Leith in a similar way to Trainspotting, but it's a more conventional narrative structure, although it does follow them from being kids to the present; one of the main characters is Juice Terry so it's worth it too find out more about one of the best characters in Porno. Skagboys is decent too and well worth reading. But Filth, Maribou Stork Nightmares and glue are the best I'd say.