YouTube Song Downloader is an audio and video downloader. It is a very well-thought tool that allows you to download the audio of YouTube videos and convert it to .mp3 files for playback on any player. The application allows you to set the quality of the MP3 files and the format for video files. However, keep in mind that if the video from which a song is ripped is of low quality, the resulting .mp3 file will not be any better.
YouTube Song Downloader uses a search engine to find videos on YouTube. You have to type in the name of the song and a list of results will be created. You can preview the videos on a pop-up window and decide from there whether you want to download the audio of the clip or simply download the whole video clip to your computer. Thus, this application doubles as a video downloader. The only limitation that I see after a few minutes of use is that you don't get many results. You probably get 20 or 30 results for each search. But, if you are looking for a song, that should be enough.
YouTube Song Downloader worked flawlessly in my testing. The audio was of OK quality, as expected, and downloaded videos played well on all video players I had. This is a free tool, but they accept donations.