According to the Guardian's Sean Dodson, though he seems focused more on decorations and amenities than books:
My favorite was the old used-book store in the basement of the University YMCA in Champaign, Illinois, though it wouldn't appear on anyone's "most beautiful bookstores" list. The proprietor had established a large collection of the old Doubleday Image paperbacks when he was a student in the 50s and 60s and slowly selled them off at the store along with thousands of other goodies.
UPDATE: Welcome, poncers! Feel free to browse around. There's a morning coffee routine/google workout and various & sundry links to whatever I stumble across on the net.
And the Word was made flesh, and dwelt among us.—St John of Patmos
And in these days of Lent they shall each receive a book from the library, which they shall read straight through from the beginning.—St Benedict of Nursia
A facility for quotation covers the absence of original thought.—Lord Peter Wimsey
A Quinn Martin Production