Visited Arizona with a couple of architect friends, so the Phoneix Library had to be a stop :)  The outside of the building isn't nearly as impressive as the inside.  But wowie, when you're inside, it's like a whole other world.  The details and attention to spacing are amazing.  Not to mention it's a LEED certified building (green building) which is pretty cool.  If not to check out books, you gotta at least check out the building.