Maybe I've become an Rdio fanboy, but I think it serves all of my needs when compared to the other services. I never really liked Grooveshark because of its incomplete interface. I could be wrong, but it doesn't seem as though there's enough money from a free service to support the artists. I'm also not a fan of cloud storage because I really don't "own" much music, and there's currently not an iPhone app for the Amazon store.<p>So why do I love Rdio? Well, for $10/month I'm able to stream and locally cache pretty much any song I'm into at the time. They've also done a stellar job at signing indie labels, especially the ones here in NC. It also has my network of friends, so I can see what they're into.<p>Like I said, I'm really biased but hopefully you'll find some useful info there. :-)