There's really nothing I can say about Mr. Gaiman's writing that hasn't already been said, and quite eloquently, too. So I will say this -- Neverwhere is somewhat less cerebral than, for example, Anansi Boys or American Gods, which I think could make it somewhat more approachable for some readers. It's a modern urban fairy tale, chock full of delightful and/or terrifying characters. The dialog is excellent, and the story completely entertaining. You should read it.

PS: The audiobook is narrated by the author. I would not have predicted that Mr. Gaiman would be one of the finest voice actors I've ever heard. But there you go.