Here's a fact that baffles both me and my wife. I like reading young adult books. I haven't been able to boil the reason down to one nice sentence, but what I have worked out goes something like this: Young adult novels have plots that are just as complicated as adult novels, but they move faster. At least for me that's true.
I have read most of the Percy Jackson series by Rick Riordan and most of the Artemis Fowl series by Eoin Colfer. All of the books that I've read in each of those series start with a bang and keep chugging until the end. The Artemis Fowl books seem more "adult" in nature as they are about a child who is a criminal mastermind.
Jeff Vandermeer has an interesting interview with Eoin Colfer over at Amazon's Omnivoracious blog. Colfer has written the next installment in the Hitchhiker's Guide to the Galaxy series. Go check it out. It's a fun read with lots of personality coming across in both the questions and the answers. Just the kind of Q&A that I like.