IMO the two best tracks to demo or test any system

Jackson Browne-"Late for the Sky" or "Before the Deluge"

Shawn Colvin-"Never Seen Blue Like That"

http://www.youtube.com/watch?v=Q2CkOEThLLw

Vinyl versions of:

Rudy- Supertramp
Babylon Sisters- Steely Dan

Greatest hits usually get most of reprocessing of the original materials to match sound characteristics of one to another and therefore not on my list to demo.
Had LZ classsic records 180g pressing, but was not impressed compared to first press. It's definitely more quiet, but dynamics are sacrificed and makes me bored or is it just Led Zeppelin that I'm tired of listening to on all formats.

Small releases from the small record companies sound best to me:
CMP label: Charlie Mariano,Philip Catherine,Jan Garbarek,Bo Stief -- "October" on vinyl
Sky label: Irmin Schmidt -- Impossible Holidays on vinyl
WEA label german pressing of Carla bley's "European tour 1977"
almost ECM vinyls (especially german presses) are all great to demo.

@Mlsstl
Once a mastering engineer told me the more data you add to a cd the more compressed it will sound so reprocessing is used to eliminate the volume from track to track. Even though digital he used the example of how sometimes the inner groove distortion issue.

Thanks for the clarification.

@Czarivey
I have the 200g pressing I didnt know that 180's were even out there.