Okay, simple. Can someone provide the title (and preferably an URL) to a book about computer security that any security specialist must have in their library. And yes, I mean paper books, no PDFs... Something that would look good on my bookshelf and might also be very educational.
A link to Amazon or other online bookstore would be real welcome.

I am talking about security in general, btw. Tips and tricks to keep your compuer safe, for example. Or website security. Can be Linux-related, Mac-related, Windows-related or just generic. Anything useful.

Who knows a good title? (Please post only one title.)