"Must-have" SACDs Out There

I just got a Sony XA-777ES SACD player. I was initially disappointed with the performace. I could not hear much difference between the CD layer and SACD layer on the Sample CD that comes with the player. I went out and bought the "Norah Jones: Comes away with me" SACD and started listening, then I begin to realize the advantages of SACD. As far as I can tell so far, the music is smoother, less harsh, and has a overall quieter background. What else should I be listening to? What are the "must-have" SACDs out there?