Great Downloader easy to use can convert into multiple file formats. Fast and impressive
Video DownloadHelper - Browser extension to download videos from the Web
MP3 Converter - Mp3 Converter is a free to use as YouTube to MP3 converter that allows you to convert and download YouTube to MP3, MP4, F4V and 3GP formats.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
Absolute Audio Converter - Absolute Audio Converter is an award-winning audio converting software.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.
Online Audio Converter - Online Audio Converter is an online tool that converts any audio file into multiple formats including,mp3, wav, iPhone ringtone, m4a, flac, ogg, and more.