Some of my favorites right now:
I have so much more - several boxes worth, really - but most of them are in the states (I'm living out of the country, currently) and I do miss them dearly. This awesome thread is threatening my wallet. xD haha~
EDIT
I just remembered that the MET has a TON of art books, etc that you can download for free! HIGHLY recommend to just peruse and stuff! Download pdfs if you want to, as well! I know I have. c: