iDesktop is another great youtube converter. This one has the converters built right in to the interface, so it is very intuitive. You can also select widescreen or standard viewing size when you watch the videos.

Their description says it best

" is an incredibly cool dynamic web 2.0 application, with a terrific modern design, that brings you a better way to search and watch YouTube videos. Not only (that) but you can download YouTube videos!
This is basically adding functionality and experience to what "should be" there. The possibilities of the site reach far beyond that. It gives you the chance to create your own environment for watching video clips, saving them and sharing them with friends."

The only possible downsides I have found:
1. You have to register..but it is free.
2. No mp3 downloads at this time.

Try it out and let me know how it works for you.

h/t mtkamike