Great Downloader easy to use can convert into multiple file formats. Fast and impressive
Video DownloadHelper - Browser extension to download videos from the Web
4K Download Online - Download music from YouTube to Android, SoundCloud to Android, Facebook to Android, Vimeo to Android, from browser to device or to desktop directly.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
ImTOO Download YouTube Video - ImTOO Download YouTube Video is a free YouTube video downloader software!
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.
Video Downloader Professional - Video Downloader Professional (VDP) is an pretty smart and fast tool to catch videos from YouTube.