Well, damn if you’re almost out of Gaiman. Have you read the Sandman series? It was released as a comic and is now collected as a graphic novel in 10(?) volumes. Epic Gaiman storytelling.

Join Me – Danny Wallace

Yes Man – Danny Wallace

Martian Chronicles – Ray Bradbury (save for October though, it feels like Autumn to me)

The Phantom Tollbooth – Norton Juster (kids book that adults tend to love far more than kids do, just terribly clever)

If you haven’t already, you’d probably like pretty much anything by Douglas Adams or Terry Pratchett. Neither have the dark edge that Gaiman has, but the Brit wit is there.