Banned Books are the Best Books. You can always tell which faction of crazy has the biggest stick up their butt on any given year by looking at the lists of books they bitched about and why.
Yeah, The Satanic Bible isn't really a book you need to own unless you need it as part of a collection or something [...yes, I own it]. Reading it once is usually enough for most people. I would say that it's main redeemable feature is just the shock value of the title sitting on the coffee table or holding it when there are Jehovah's Witnesses standing on your doorstep. ;D I prefer to mix things up a bit if I'm expecting irritating company - nothing causes brain hemorrhages faster than a tasteful display of Crowley, Harry Potter, Psychology Today and Dilbert.
I accidentally left a book on southern voodoo doll practices out in the living room that I had just finished and there was apartment inspections yesterday. The people in the office seem really energetic today - you'd think it was a four-day weekend for as fast as they seemed to get out of the building.