I second the nomination of MTT's recordings of the Mahler symphonies. These discs really take advantage of the huge dynamic range available on SACD/DSD. I'd also add "Blue Country Heart" by Jorma Kaukonen (Columbia) if you like folksy/bluesy/country Americana. It's another pure DSD recording and offers superb presence, 3-D imaging and clarity.
Best sounding SACD's to show-off system
I like to show-off my Wilson Audio W/P6s and Krell 350mcx to friends and try to get them to understand the rush of high-end audio, and I have to some degree, but what SACD's out there that are recorded best! Something that will really make them melt with goose-bumps. Thanks!!