Google Play Music Family Deal
Now you can pay $14.99 for Google Play Music for the entire family (up to 6 users). This is the same price for the same number of users as Apple Music and Spotify will be soon be matching the two services' price scheme.
What's the differences between the music streaming services? Not much, they have huge library (in the tens of million of songs), allow offline listening, and offer playlists based on a certain song, artist, or mood.
Where Google differentiates from the other services is that it includes YouTube Red. The benefit of YouTube Red is watching YouTube videos ad-free and allows users to download YouTube videos for offline watching. For me, Google Play Music is a no brainer for families (or people willing to share services with others, or split the cost); especially since everyone watches YouTube videos.