Economics Book Catalogue (The Economics Network, U.K.)
The Economics Network of the of the U.K. offers an extensive guide to textbooks and books that might be used in teaching. While of course there is a U.K. focus, it also lists a very large number of U.S. texts (which are typically separated in the subject listings). They are organized by titles, authors, and subject (i.e. course), and this index is searchable as well.