re: What is better, Google music? Spotify? or iTunes?

depends on what you want. Does owning your music mean anything to you? If not, Spotify is the way to go. As far as Google Music v iTunes, I pay $25/year for iTunes Match and have loved it so far (2.5 years) even though I don't listen to music that often. When you use iTunes Match on an iOS device, it will download the song to your device while you stream. This means that the songs I listen to most often are already on device and don't use data every time I listen to them. But if I want to listen to one of the 24,000 other songs not on device it's no problem.