One of my fancy-schmancy bibliophile sites just sent an email titled 30 books you might read for the cover alone http://www.abebooks.com/books/great-fiction-covers.shtml?cm_ven=nl&cm_cat=nl&cm_pla=cme-nwb&cm_ite=feature
If you go to the link above you'll see some examples of what I think is some pretty good design and art direction. The three I've posted here I especially like. I guess I like ideas no matter where I find them.