Web ScrapBook - A browser extension that captures the web page faithfully with highly customizable configurations.
Website Downloader - Download source code from any website
HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Offline Pages Pro - Offline Pages Pro is probably the world’s most advanced offline browser.
Archivarix Website Downloader - Website online downloader and Content Management System (CMS) existing site converter.
wpull - Wpull is a wget-compatible web downloader and crawler with WARC and Python/Lua scripting support