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

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.

Here are a few well recorded performances that have to sing in captivating fashion, or I wouldn't want the system!  Each has its "tells" for revealing the sonic influence of a system change.

Jazz:
Shelly Manne & His Men - at the Blackhawk, Vol. 1 "Summertime"
Charles Mingus - Mingus Ah Um "Goodbye Porkpie Hat"
Grant Green - Idle Moments "Idle Moments"

Classical:
Bach, Passacaglia and Fugue in C minor, BWV 582, Peter Hurford on organ
Bruckner Symph 7, Gunter Wand & NDR - "1st Movement" is telling
Debussy, Zoltan Kocsis on piano - "Images, Livre 1:  Reflets dans l'eau" 
Enrique Coria - Latin Touch "Verano Porteno"

Rock:
Beck - Odelay "Where It's At"
Neil Young - Live at Massey Hall "Old Man"
Low Reed - Magic & Loss "Power and Glory"
Pink Floyd - The Wall "Hey You"

Interesting choices listed above.  Love the music selection but not many I would use for evaluating audio equipment.  I generally look for live recordings, and trio jazz music or music with sax, piano and stand up bass.  No electronic music or rock & roll as the recordings are usually compressed.  I use piano recordings so that I can evaluate the weight of the notes, the decay, and how much wood on the piano I can hear.  Sax I want to hear if I can hear the reed vibrating, and the tone, vocals hear the air coming out of the mouth and stand up bass the wood and definition.  Once I hear all that, then I cam confident that Stevie Ray and Duane and Dickey will also sound good.

Happy Listening. 

I agree with BigKidz that a variety of "live recordings (acoustic & electric) is essential, as is songs where the notes have a lot of decay (particularly acoustic piano). Big picture wise, have some male and female vocals, while also focusing on guitar, bass, drums and keyboards. Finding something with a string quartet or a full orchestra is also a good idea. Little picture wise, any song that gives you "goosebumps" is an automatic candidate; or, any song that you pick up subtle details on headphones but not your current speakers would also be good.

Some of my recent "live" favorites are: "Fools in Love/For Your Love" - JOE JACKSON; "No More Buffalo" - JAMES MCMURTRY & "First and Repair" - MONTE MONTGOMERY.

Some of my recent "studio" favorites are: "Get Inside" - JOHNNY A; "Try, Try, Try" - ALEJANDRO ESCOVEDO; "That is Why" - JELLYFISH or anything from "Turn Of The Cards" by RENAISSANCE. I also agree with Irish_Tim that "Babylon Sisters" by STEELY DAN is an excellent choice.

Good luck and happy speaker hunting!