Momixa - Pick two songs and get the perfect mix
Wacht.tv - Reddit meets MTV, discover music videos!
Music Suggestions Ninja - Enter an artist's name & find similar, lesser known artists
DiscoverWeekly.dev - The playlists made by devs, every Wednesday
Boil the Frog - Create a seamless playlist between any two artists
SameTunes - Music social network to compare, share, and discover music.