What are your top songs that you use to evaluate a new high end purchase ?

Two from Procul Harum's A Salty Dog: the title track and "The Devil Came From Kansas"!

You obviously like the Stones - Monkey Man and Beast of Burden should be on your list.

The Sounds Of Silence. 

I think part of it is listening to a wide range of  different material in recording style, scale, range, dynamics and other attributes. In term of what I use, it varies, but one constant is Between the Lines- Janis Ian. I am well familiar with the recording, it has much to commend it whether or not you like the music, from spare arrangements with female voice to more elaborate production including horns, strings. The original issues were cut by RL, for what that's worth, and sound pretty much identical to a test pressing I have. But, part of the process is seeing (or hearing) where the illusion fails, or isn't as convincing. Some of this results from the source material itself, so it does make sense to use recordings that are familiar to you. 

After all of these years : Jazz at the Pawnshop, Vol. 1, SACD. Enjoy ! MrD.