What is the VERY BEST CD album you've ever heard?

Any SACD on a PS Audio SACD player. And standard CDs shine brighter as well. Agree with the above regarding Live at Fillmore East, and Take Five.

For the category of great live CD performance and mediocre recording quality, I would nominate Delaney & Bonnie & Friends On Tour, With Eric Clapton.

all-right.

Let's call the common stuff mainstream whether it's rock or pop or hop of any kind.

Mainstream usually can be found in thrift stores for less than a buck

Blood Sweat and Tears, Original Master Recording. 24 kt Gold Plated. 

I've had this for a while now, but finally cracked it open: Spheres II by Delerium.  Spacey, ambient, juicy, spooky, moody instrumentals.   Sounds exquisite. 

@tylermunns  

Terms "pop" and "rock and roll" have been in use by music industry professionals, since early- to mid-1950s.  I entered into what I thought was a discussion.  If this is your idea of a game, you can declare yourself the winner by forfeit.