Here's a very limited edition art book by Darwyn Cooke (wiki).
It's published by Brandstudio Press and has only 48 pages. 48 pages of great art.
The variety of style is great even with so limited pages. The illustration printed big, show amazing details, such as brush strokes and water color gradients. Particularly impressive is the untitled piece drawn for The Spirit. It's well composed and lit, just like how Will Eisner might have done it. The cross hatching for the shadows are incredible. You can see it from the last 3 seconds of the video.
There's a more detailed review of Retroactive by Charles Yoakum.
If you're interested, you can check out the blog of Darwyn Cooke, created by his friend, Calum Johnston.
This book is not mine. I borrowed the book from Jonrob, who bought it in San Francisco. His words to me as I left the office,"Take care of the book."
He didn't look amused.