Booxter: Your personal librarian
Booxter offers advanced book cataloging features in a very intuitive interface. I easily consider it one of the best in its category thanks to its flexibility and GUI. You have a number of ways to organize your books including smart lists, tags or filters. Finding any book is also very easy thanks to advanced search capabilities.
Importing books is what worries librarians most though, and it's where Booxter gets it right. You can import from different types of applications or text files and export your lists in a number of ways including CSV and HTML or even to your iPod. Booxter also offers special features that really separate it from the rest of the catalogers. There's a fun little quiz game to test how much you know about your collection and keeping track of books lent is very intuitive.
Booxter seems to have no trouble handling large libraries and can now even support movies, music, and comic books. One minor drawback is that it won't save manually imported cover pictures.
