Openwhyd - Collect and Share the tracks you love.
Gnoosic - Even if you don't know what you are looking for - gnod will find it.
SoundClick - SoundClick is a music-based social community.
Musicroamer - A visual Pandora for discovering new music
Music Smasher - Find any song. Music Smasher searches Spotify, Rdio, SoundCloud, Bandcamp, and YouTube.
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.