What CDs to buy

Any of the Steven Wilson remix's (Chicago - Jethro Tull - XTC - Yes) or any of the recent remasters of The Beatles, Joni Mitchell or Pink Floyd will get you started.

Radiohead OK Computer 

I practically never listen to rock, but this one blows my mind.

While my instincts warn me against wading into such waters, I can’t resist. To come onto an "Audiophile" site in search of recommendations for recommendations of CD’s to purchase does nothing less than provide evidence that audiophiles care about the sound quality of recordings more than the music itself. My God, @dhite71, reconsider your priorities! Do you use your recordings to show off your hi-fi, or rather use your hi-fi to increase your immersion into and appreciation of the music contained in your recordings?

Jvc xrcd either generation.  Likely  the best. Mobile fidelity  sound lab gold cds ok. Chesky  very good. Ma very good. Try some of those audio file  recordings  on those discs

Welcome aboard the CD train.  I have a AR refCD7 that i still use a lot. Recently got a DCS Bartok to take me into the realm of streaming.  I find that I prefer the sound of cd's to most of the hi rez on Qobuz but not always- for instance, to my ears, most Allman Bros versions sound better streamed.  I highly encourage you to order a copy of Rupa and the April Fishes "este mondo".  It is one of the finest recordings I own and I find the music very interesting too.  "trouble" is a great reference recording.  The CD version is particular ambient.  Leonard Cohen's "ten new songs" is another one with similar characteristics. Happy listening!