Technically, I guess, Banned Books Week ends tomorrow, so you could have been celebrating this whole time. Sorry I didn't tell you sooner!
I was intrigued to discover that the book that got the most complaints last year was one by Dav Pilkey, Captain Underpants! It's a favorite in our home (which tells you a little something about us!). Other books receiving complaints include the Hunger Games, the Harry Potter books, and The Lord of the Rings. Go figure!