I think Soundcloud is great. It took over from MySpace as the most popular way for artists to share their music, and give listeners access to music they might not be able to find in stores or in iTunes- and it's free!
I think it's a lot better than MySpace, though. It's more interactive, so users can easily interact with each other and musicians with their fans.
It is also very current in the way that tracks are presented. There is a "Trending" section, which shows you popular tracks in the same way that Twitter shows you trending topics. This is a great way to discover new tracks.
The other cool thing about Soundcloud which makes it different to other streaming sites like Spotify, is that it also has an "Audio" section which features popular podcasts and radio clips.
