Gnod - the Global Network of Dreams is another interesting place to find recommendations of various sorts. Flork is a profile site whose login takes you to Gnoosic, Gnooks, and Gnovies. Flork gives you your own profile page. It looks like the technology is still fairly early stage, but it’s an interesting thing to explore.
musicplasma: the music visual search engine is pretty impressive in its ability to show visual links between similar artists, and the database is pretty extensive as long as you stay out of the classical section (though I can out-obscure it from my collection of European goa trance). You’ll need to open up your browser to a rather wide view to use it.