Great poll idea, Zeeb! You only allow for one choice, so I selected "other". My preference is still to buy rather than rent the music I love but do I enjoy these three streaming services regularly, in order of use:
1. Spotify Premium - my "go to" for our MG projects, new music I'm not sure I want to buy, and older music if I'm not where I can access my library.
2. Pandora Premium - I dabbled with the free service for years just for the fun of building genre stations with my opposable thumbs. Last Christmas I jumped into the paid version to create a holiday music station with the element of surprise. The biggest surprise was that Mrs. Ojai loved it. Now we use the classical, jazz and oldies channels when we entertain, with more ideas on the horizon.
3. LivexLive (formerly known as Slacker Radio) - the concept of this service is similar to Pandora but the stations are more actively curated. I have been enjoying their World Station for years.
Spotify is handy to me so that I don't have access my personal library while at the office or in the car. It's the size of Spotify's library that I find most useful vs high fidelity or a connection to the Apple ecosphere.
And frankly, I listen to Spotify a lot at home too. For many years the fidelity on my home system has been adequate but far from audiophile, so there isn't a lot lost in playing Spotify vs. CDs.
I find Spotify isn't that bad fidelity-wise. If you use the high quality option, it's 320K Ogg Vorbis and almost no one could tell the difference between it and lossless in a blind test (including me, probably).
That said, I notice that my local FLACs have a smoother, more relaxed sound on my headphone system. Whether that would hold up in a blind test, I don't know.