Here's another vote for Amarra. I tried both the Pure Music and Amarra demos and Amarra sounds significantly better with my rig.
PS Audio Power Plant Premier > Mac Mini 2.53GHz/4GB > Amarra Mini 2.0 > Halide Bridge> Cambridge Audio 840C > Acoustic Zen Silver Reference II > Arcam AVR350 > Acoustic Zen Shotgun Double Barrel > Vandersteen 2Ce speakers (combination of LessLoss and VH Audio power cables w/dedicated circuits)
PS Audio Power Plant Premier > Mac Mini 2.53GHz/4GB > Amarra Mini 2.0 > Halide Bridge> Cambridge Audio 840C > Acoustic Zen Silver Reference II > Arcam AVR350 > Acoustic Zen Shotgun Double Barrel > Vandersteen 2Ce speakers (combination of LessLoss and VH Audio power cables w/dedicated circuits)