I recently purchased two Batman Unwrapped books (Court of Owls and Hush), and wow. These books are awesome. I love seeing the raw pencils of these great artists. I am a big fan of the Artist Editions from IDW and these books are similar, though smaller and they contain full story arcs.
I think any Original Art fan would enjoy these.
"Fairy tales do not tell children that dragons exist. Children already know that dragons exist. Fairy tales tell children that dragons can be killed."
-G. K. Chesterton