Picture/Coffee table books
Sometimes, you buy books for their pictures, not their content — and I found both of these books on the remaindered pile at Borders, they were a cheap addition to the growing pile of books next to my couch.
There are dozens more, of course. And, if you aren’t as dedicated a collector as I am, the library has shelves full of the things to browse through.
You might, of course, be more interested in the actual history and reference books.