To some extent the best sounding recordings were made in the late 50s thru early 60s. It was the time of the classic tube recording equipment and by necessity engineers had to keep the recording process simple. They had at most 4 channels to work with and very limited EQ and compressor/limiter options. The current technology can easily match the sound quality from that era, but for a variety of reasons, it's rarely done.
Surprised by quality?
I've been listening to my music on crappy speakers for years now. Finally, I bought a decent pair of speakers, and have been listening to all of my music over again, searching for the quality of reproduction and tone, and all that good stuff. There have been a few recordings, though, that have surprised me with their quality. One of these is Seven Mary Three-- American Standard. The cymbals sound like cymbals, the drums sound like drums, and the guitar has exactly that crunch which I liked to pretend it did with my old system. Also, there are the Glenn Miller recordings from the 30's and 40's. I expected digitally remastered music from that long ago to lack something. I've discovered that they do not in any way. What recordings have you listened to that surprised you with their high(or low) quality?