"Litmus test" songs


I know, I know, you can't evaluate a component, let alone a whole system based on a single piece of music, or even a half-dozen pieces. That said, are there any songs out there that you use as litmus tests when evaluating a purchase? Some song that you use when you say, "If this gear doesn't sound good with this song, then I don't care what else it does, it's going back"?

For me the Number 1 is "It's For You" by Pat Metheny Group.
macdonj
Paul Simon - Graceland - Boy in the Bubble, Graceland, Diamonds on the Soles of her Shoes

Steve Miller - Born 2b Blue - God Bless the Child

kd lang - Absolute Torch and Twang - Luck in My Eyes

Talking Heads - Naked - Nothing But Flowers
Talking Heads - Stop Making Sense - Burning Down the House, Life During Wartime

Miles Davis - Kind of Blue - So What (Columbia Mastersound) - only the bass in the beginning

Those will usually show up deficiencies pretty quickly. After those, I go to acoustic music, etc.
Another trick I use in testing out equipment is to try out flawed recordings. e.g. If you have a recording where you know that the guitar has a marginally harsh edge, then a great system doesnt correct this for you, or it will fail elsewhere.
Here are some albums I always take out.

Soundstage: Paul Kelly, "May 1992"
Electric guitar/decay,surge and whomp: Midnight Oil, "Earth and Sun and Moon"
Acoustic: James Taylor, "Fire and Rain"
Live Ambience: Neil Young,"On the Beach" and "Zuma".