alibris
Unlock a treasure trove of rare, used, signed and other hard-to-find books. This site also features a New Yorker cartoon of the week and crossword puzzles to keep your brow high.

amazon.com
In addition to selling (nearly) everything under the sun, Amazon.com has an eerily accurate book recommendations service. Also a plus: the rookie reviews posted by Amazon.com shoppers and the In The News selection of books recently reviewed on NPR and in other news outlets.

barnesandnoble
Browse by subject, check out the recommended selections, and purchase a pound of Starbucks.

borders
NY Times Bestsellers are 50 percent off, as are forthcoming releases.

fatbrain
Fatbrain promotes itself as the Internet's most comprehensive bookstore for professionals. But don't think that means Fatbrain is all work and no fun. You can still find a copy of "Angela's Ashes" amidst the computer and information technology tomes.

powells
The famed independent bookstore's online store; Powell's is an intellectual haven.

varsitybooks
Save money for tuition by buying textbooks and other collegiate supplies from this online college bookstore.