I used to use Zamzar but Google told them to stop. I found another one but the same thing happened. I want to know what you guys use and if it still works. I know you're all a bunch of dirty pirates so don't even tell me you don't use one. *shot*
I used to use Youtube MP3, but for the actual video, i use Youtube Downloader, I can PM you the key for PRO if you want, since it works any amount of times.
http://download.cnet.com/YouTube-Downloader/3000-2071_4-10647340.html (http://download.cnet.com/YouTube-Downloader/3000-2071_4-10647340.html)
I use one by DVDVideoSoft. It comes with a bunch of other software such as a YouTube downloader (MP4 videos), a bunch of file converters, and some other useful programs. And the youtube to mp3 is pretty great too, it gets the job done for me