filtermusic.net
Filtermusic summarizes all the common genres, but is primarily focused on electro/dance/pop stations. It elects on listener popularity and freshness or something.
Which is why there are just a dozen categories with around 20-30 stations each. Still useful if you don't like to browse around a lot.
Like the Xiph plugin this channel provides two/three fetch modes. There's no speed or feature differences this time. You might prefer the buffered mode, as it reduces update requests, but still allows refreshing lists.