With respect to label consolidation, this is an interesting video that, as detailed as it is, still just barely scratches the surface of recording labels(why Freddie Mercury is splashed on the video cover..no clue):
https://www.youtube.com/watch?v=uoFWpZ4CDs4
As for labels..I’m primarily a jazz listener. Off the top of my head, for pure, consistently A+++ recording quality; ECM, ACT, Chesky in no particular order as they are all terrific. The music they publish varies in likability (completely subjective), but you’re pretty much guaranteed examples of what excellent recording quality sounds like. Oddly enough, though not my cup of java, Madonna was pretty OCD on her recordings too.
Blue Note captured a near infinite number of jazz artists, groups, and recording dates. Much of the prime stuff for traditional jazz lovers was recorded in the 50’s and 60’s. Unfortunately, much of the time, Rudy van Gelder was the recording engineer. His mom’s living room and later studio recordings can be hit or miss with respect to the actual recording quality. Some early McCoy Tyner recordings, to me, are unlistenable simply due to poor recording quality. I suppose they were OK at the time, but other 50s & 60s recordings have stood the test of time MUCH better than a fair bit of RVG’s output.
Prestige recorded some great jazz dates.
Columbia was great too up until the ’73 Bad Day at Black Rock (Columbia Jazz Purge)..look it up..