Googleplex, which music streaming service do you use and why ?

Title says it all really. Which streaming music service do you use and why do you prefer it to the others ?

Personally I'm in a period of seeing what all of them offer. Rdio is my choice at the moment from a subscribing point of view, but I occasionally am using Spotify Free if Rdio doesn't have a particular track.

For me, Rdio has the best looking app of all services, plus gives me the ability to pick up from where I'd listened to on all my devices, which is a HUGE plus point for me.

So, what do you use and why ?