I love this stunning library at Trinity College in Dublin. I've strolled through it many times during my trips to Dublin. The Long Room a the Old Library. If you ever get to Dublin, don't miss this jaw dropping piece of architecture and history.
El Ateneo bookstore / Buenos Aires Argentina This bookstore, one of the biggest of Argentina (if not whole southamerica), is located inside a theater called Grand Splendid on Santa Fé Ave. This theater was bought by Grupo IHLSA (the owner of El Ateneo).
Antique vellum books are getting quite popular in decorating circles. They are very beautiful but as an avid reader my biggest pet peeve is book shelves filled with "books by the yard" that look good but you know no one reads.