The Sweet Setup's music streaming service of choice? Spotify.
Spotify is the go-to choice right now because it has nearly every feature other services have, it has the most users (your friends), plus it’s gotten really good at what it does.
Special shout out to Discover Weekly playlists, which have been on point for me the last few weeks:
If you’re less interested in doing the work, Spotify now features a personal “Discover Weekly” playlist updated for each user every week. The Discover Weekly playlist has been widely praised for its song selections, despite being powered by an algorithm.
I even agree with their major criticisms of the service:
However, if you manage to discover new music, sharing it still remains a pain. Since Spotify has a free tier that is currently used by the most people (75 million worldwide as of June 2015), sharing a Spotify link has the best results. The company’s embeddable playlists remain as frustrating as Adobe’s Flash, but the communal aspect Spotify holds is nothing to sneeze at.
Unless I know that somebody is a regular Spotify user, I'll almost always pass them a Soundcloud or YouTube link if I find a song that I think they'll like. And even though Spotify has a built in messaging platform that allows you to share tracks with friends, I've found their notification and badging to be so unreliable, that I often don't even know that somebody has shared something with me until days later.
There's a lot of music streaming services out there now, and I have a feeling that the first one to do social features right that will be the the one that is most successful in the long run. Spotify is close, but they're not there yet.