WP's Tenets of Parenting, subheading: The Scandalous Bookshelf. If you, as a parent, don't have a bookshelf devoted to titles that will surely mortify your teenage children, you aren't doing your job.
I think on this score I may perhaps be a bit overzealous. There are at least a dozen religious books that spring to mind -- if you cleared the words from the covers, the graphics alone would be cringe-inducing. Then there's daddy's sci-fi shelf. And Batman comics? What's that all about? Oooh, look: Lou Reed's Collected Lyrics & Verse -- "Hey, I'm still, like, edgy -- y'know?"
I can't resist. The urge to collect and display books that will embarrass my kids -- if not now, then later -- is just too strong. It was this very principle that explicity informed my recent purchase of Michel Houllebecq's Elementary Particles (well, that and its remaindered price of $2.99). It's right there on The Scandalous Bookshelf, just waiting for the day when one or the other child will say, "Eww -- what's this doing here?" And if I don't hear those words by the time the youngest turns 15, it disappears.
(Re: Houllebecq, when all is said and done and read, I have to admit I agree with this guy -- link from ALD. And if you want more photographs like the one above, go to the source: Diane Asséo Griliches. Link from BookLust.)