HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Diigo Web Collector - Bookmark, Archive, Screenshot & Markup - All-In-One Web Collector, must-have research tool
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
Onenote Web Clipper - Quickly capture any webpage to OneNote where you can easily edit, annotate, or share it. Clip the full page, or clip only the article, recipe, or product information you really need.
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
Pocket - When you find something you want to view later, put it in Pocket.