HTTrack is a free and easy-to-use offline browser utility. You can download the contents of entire Web sites from the Internet to a local directory for offline viewing. Simply open a page of the mirrored Web site in your browser and browse the site link by link as if you were viewing it online. HTTrack also can update existing mirrored sites and resume interrupted site downloads. The program is fully configurable and includes an integrated help system. It crawls M3U and AAM files and can cache to a ZIP file.
Editor's review of HTTrack Website Copier

This program copies Web sites from the Internet for offline browsing. The installation actually allows you to choose not to install a Start menu folder, a rare favor. HTTrack Website Copier downloads sites into a My Web Sites folder it creates, which you will have to remove manually if you uninstall.

On start-up, a dialog box immediately asks what proxy server it should use, which is off-putting. The sheer number of configuration options for mirroring made us dizzy. You can enable or disable external link crawling, downloading of classes of files such as DOC or JSS, and just about anything else. The default settings didn't preserve some aspects of some complex sites, such as font and background color, but surely that is just a configuration option in one of the many menus.

Ripping an entire site took less time than clicking through a couple pages of it online. Whether you're a casual user looking to grab a collection of pug pictures or a Webmaster wanting to work on your site from a new computer, this is well-worth the free download.