There are literally millions of tracks we can use to evaluate our stereo system setups, yet most wouldn't be of much help. Without some form of acoustic reference material, it's nearly impossible to know when it is right or wrong. What's the proper sound of a fuzz tone guitar? Unless you had attended a Jimmy Hendrix concert in your youth (and had a perfect memory), you'd be hard pressed to know if a modern system rendered his guitar properly.
Whenever I start to set up a system I do my best to keep my source material simple and natural: a familiar voice, an acoustic instrument I know well. The more familiar I am with the piece, the easier it is to know when I've nailed the tonal balance, imaging, and dynamics.
What's wonderful is we don't need to use the same tracks all the time. As long as we stick to the principals of simple, natural, and familiar, just about any track works equally well.
Perhaps the biggest mistake I see people making when setting up systems is the use of big, complex, unfamiliar music or, worse, electronic music without any known reference.
When setting up, always go back to basics.
