IMO the two best tracks to demo or test any system

Vinyl versions of:

Rudy- Supertramp
Babylon Sisters- Steely Dan

Thanks for that link Mofimadness what a beautiful song going to have to buy that one

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.

Either you misunderstood the mastering engineer's description of the issue or his understanding of digital music files is incomplete.

And, whether "greatest hits" CDs are remastered or not depends on two issues. One is volume normalization for tracks from different albums and the other has to do with bringing the reissue "up-to-date" with the current fads & fashions in the music industry. Neither has anything to do with how the CD stores digital info.

Inner grove distortion is an issue relate to vinyl LPs and ties to the fact that the velocity and tightness of the radius differ for the inner grooves of a LP which affects how the stylus picks up the physical groove impressions.

This issue doesn't affect CDs -- other wise the distortion would corrupt the signal and no data or program CD would ever correctly install. (CDs actually begin play at the innermost groove and work toward the outside edge which is the opposite of LPs.)