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

They learned their trade playing rock and roll in Hamburg before they became a pop band and towards the end of their career there are some distinctly rocky tracks, on the White album particularly. Fitting rigid categories to bands isn’t always easy, especially if they start playing different tunes part way through their careers.

Back to the topic, I’m rather fond of Thrack (King Crimson) and Grace (Ketil Bjornstad), both CD releases. The latter is Scandinavian jazz settings of poetry by John Donne and is a warts and all recording so not for some with more audiophile sensibilities.

guessing yor're asking about obscure good albums ..

Leafhound 'Growers of Mushroom' -- elements of Grand Funk, Deep Purple James Gang rolled into one.

Szobel 'Szobel' elements of a Zappa fusion album. He was Bill Grahams nephew, so he got an album deal, was high strung about recognition, so disappeared after recording this.

Layla Revisited - Live at Lockn'     Tedeschi Trucks Band

Delivers on the potential of the original  Layla.  Recorded live, the music and sound are first rate.

I Am the Moon     Tedeschi Trucks Band

Tedeschi Trucks own take on the story of Layla and Manjun. Great classic rock recorded in the studio.

Fitting category of pop band to Beatles is simple because they are pop somewhere above 90% of their career. We can call it pop-rock as well that will match even better.

There are bands that very hard to fit into any category, but the're obscure and rare and definitely not Beatles or any RR hall of fame artists. 

Maybe good example of Goz of Kermeur. Their self-titled album I think is third on my list.

A 1990 CD by the Music & Arts label called Glenn Gould - Previously Unreleased Performances of Works by J.S. Bach, 1957-1969.
This is a tough CD to find. I lucked out. It’s on YouTube. There’s also a live performance on YouTube of his unbelievable performance/conducting of Cantata No. 54.

It’s a favorite because it’s so hard to find, is not available in any media other than YouTube and contains such incredible music.

There is a version of the Soundtrack to David Lynch’s Mulholland Drive on multiple formats (the vinyl pressing goes for $400-$700 presently on Discogs) but the CD is great if for the sole reason it a) doesn’t cost $500, and b) has Rebekah Del Rio’s performance of “Llorando” (an a cappella Spanish version of Roy Orbison’s ‘Crying’) which may be the greatest vocal performance I’ve ever heard.