TubeMaster++!

Clean, adware free installers: https://board.jdownloader.org/showthread.php?t=54725

Augmentable with front-ends such as Youtube-DLG , youtube-dl is a small command-line program to download videos from YouTube and a hundreds other sites. It requires the Python interpreter and is therefore platform-independent.

Freemake Video Converter is video converter that lets convert videos to avi, wmv, mp4 (iPhone, iPod, iPad, PSP, xBox), 3gp, rip dvd, extract mp3, burn DVD and Bluray, create photo slideshow and audio visualization, cut, join, rotate and upload videos, photos and music to YouTube.

A cross platform front-end GUI of the popular youtube-dl written in wxPython.

4k Video Downloader allows to download video, audio, subtitles, channels and playlists from YouTube in high quality and to save it on your computer. This program is free for downloading videos and playlists of no more than 25 videos. This limitation may be removed by paying a license fee.

Freemake Video Downloader is a free video downloader that lets download videos from YouTube, Google, Facebook, Dailymotion and other sites either in HD, 4K, MP4, FLV, 3GP or convert web videos to FLV, AVI, MP4, MP3.

FlashGot is the free add-on for Firefox and Thunderbird to capture embedded links for all types of files (not just flash movies). -Capture all links from a page-Capture all links from all tabs-Make a selection on a web page and capture all links in that selection.-Filter the links using a mask (e.g. to download only certain types of files)-Pass on the links to your favorite download manager

FlashGet is a leading download manager and has the highest amount of users on the internet. It uses MHT(Multi-server Hyper-threading Transportation) technique, supports various protocols and has excellent document management features.

Download videos from YouTube, Rai, Rai Replay, Video Mediaset, La7, Witty TV, Dplay and lots of other websites!

The aim for webui-aria2 is to create the worlds best interface to interact with aria2. Very simple to use, just download and open index.html in any web browser.

Orbit Downloader is a Download Manager for Windows with special focus on downloading content from social media websites like Myspace, YouTube, Imeem, Pandora and Rapidshare. In addition it provides generic means to download media content from Flash based media players via its GetIt-Button and GrabIt++ tools.

Peggo.tv is a Digital Video Recorder (DVR) that records MP3s of your favorite YouTube videos and SoundCloud tracks.

Youtube Video and Audio Downloader is an open-source project, downloading Youtube videos (using Firefox download manager) in all available formats (FLV, MP4, WebM, and 3GP) with video quality of your choice. It also contains a pure JavaScript library to extract the original audio file out of FLV videos. It also shipped with an offline tool to extract audio files out of FLV videos.