Great Downloader easy to use can convert into multiple file formats. Fast and impressive
Lidarr - Lidarr is a music collection manager for downloading and organizing music libraries.
Video DownloadHelper - Browser extension to download videos from the Web
Headphones - Automatic music downloader for SABnzbd. Headphones is an automated music downloader for NZB and Torrent, written in Python. It supports SABnzbd, NZBget, Transmission, µTorrent, Deluge and Blackhole.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
Lacey - Free Music & Video Downloader
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.