I always start with Madonna - The Immaculate Collection when I'm testing anything new. Anyone else use that one? Especially "Express Yourself," it's great for testing imaging, separation, tightness, and also has good range of highs and lows. Several other good testing tracks on that disc.
I wish I could get my hands on the MFSL gold Roger Waters - Amused to Death... I borrowed it briefly from a friend a while back and the imaging and presence of the first track would impress anyone.
DiMeola et al.--Friday Night in San Francisco. SACD
Alison Krauss and U.S.--live. SACD
Cowboy Junkies--trinity sessions. CD
Stan Getz--pure getz. SACD
Emmylous Harris--quarter moon in a ten cent town. CD