A very good writer, his sci-fi (under the name Iain M. Banks) is consistently original, but his non-genre fiction is also very good. Dead Air is worth reading for the head-butting alone and The Wasp Factory is bizarre, unexpected and simply amazing.
The strength in his fiction is the characterisation. Danny Weir, in Espedair Street, is a great example. A washed-up 70’s rock star who has managed to annoy and drive off all his friends. He’s now brooding self-pityingly in a stony mansion in Glasgow. But, you’re introduced to him, you hang out with him, you drink with him and you get to know him, know him well. Though he spends the book going over everything that’s gone wrong in his life and though most of that is down to his amazingly ability to always make the wrong choice and though it may be hard to listen to an hyper-rich rock star complain about his past it doesn’t matter because you know him and, ultimately, like him. Enough to hope he finds some way out.
Oh, and the book manages to frequently be damn funny, as well.