HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Cyotek WebCopy - Cyotek WebCopy is a free program for copying either full or partial website and save it to your local PC in order to view it in offline mode later on.
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
PageNest - PageNest comes with the ability to download up to two score files simultaneously, making the best possible use of your network connection.
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
NCollector Studio - NCollector Studio is the name of a universal website crawler and offline web browser for easily downloading any website and then exploring it in the offline mode as visiting in the original state.