The Well of Lost Plots (Thursday Next, #3)
There's nothing really deep about a Thursday Next novel (aside from a tiny bit of mulling over the importance of imagination), but they sure are fun. For people who are at least marginally well-read, that is. If you don't know anything about classical literature, most of the jokes and references will be lost on you, unless you have the patience to sit in front of Google and look them all up one at a time. It's just a fast and enjoyable read, with a tiny little emotional kick.