HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
Offline Explorer - MetaProducts Offline Explorer is a Windows NT/2000/XP/2003/Vista program that allows you to...
PageNest - PageNest comes with the ability to download up to two score files simultaneously, making the best possible use of your network connection.
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.