Excellent site for music discovery – http://www.thesixtyone.com/
If you’re anti-top-40 or against any “top”, you’ll love this.
The whole site is AJAX so once you start playing music using the in-page player, you can navigate the site around and the music will never stop when you move from one page to another.
The music should *never* stop! 
The in-age player is also coo, albeit starngely resambling the Yahoo! media player
Argh, while writing this post they played foo, er, poo fighetrs on me, so I have no choice but to I take one star out of the five star review 