Let me put in a vote for "Play." I run an optical out of my iMac 3.06 into a TacT 2.2x DAC and it sounds appreciably better than either iTunes or Squeezeserver. Another popular audio player is Songbird although, personally, I prefer Play. Haven't tried Amarra, due to the cost. For those of us with audio nervosa, I suspect that the next tweak-fest will be different, "better sounding" software options to go along with our hardware upgrade-itis.