Video DownloadHelper - Browser extension to download videos from the Web
FlashGot - FlashGot is a browser extension for Mozilla Firefox that is designed to make it easy to download a whole batch of files in one go. The extension is open source and free to use, but it is no longer compatible with the most recent version of Firefox.
ClipGrab - A friendly downloader for YouTube and other sites
Flash Video Downloader - Flash Video Downloader is a popular extension for Google Chrome browser for downloading wide range of files over the internet.
Video Downloader All - Video Downloader All is the name of a free to use and state of the art downloader that is available in form of extension for Google Chrome web browser.
Easy Youtube Video Downloader Express - Easy Youtube Video Downloader Express is one of the best YouTube downloading extensions for the Mozilla Firefox that lets the Firefox users to download all type of YouTube videos via the downloader of their favorite web browser.