As probably the oldest fart here, I can assure you, (in my best Gabby Hayes voice) young whippersnappers, that some of the early recordings, even in mono, were really great. :-)
Try the jazz recordings put out in the late 50’s and early 60s on the Contemporary and Pacific Jazz labels. They are excellent. Also, for the classical buffs, try the strings on the Westminister label. For the Exotica guys, try the Command label for percussion.
RCA "Living Stereo," London "Blue Backs," and Mercury "Living Presence" recordings are the icons thanks to HP’s "Absolute Sound" evaluations, but there’s tons more besides those two labels from The Golden Era that will run circles around some of the modern recordings, especially the modern stuff that is drenched in artificial digital reverb.
Frank