Best CD player from this list

Ayre CX-7e MP is my favorite my best!

I just retired my Meridian 508.24 and I think the sound quality still holds up pretty well today. However, that model is nearly 25 years old and I wouldn't recommend buying one unless you were able to get it dirt cheap.  I doubt you can get parts to keep it running.

Thanks again for all the feedback. Based on all this info, I decided to give the 851c a whirl. I recently picked one up on the used market from the original owner. It arrived this past week and had one demo session thus far. I have much more listening ahead, but my initial impression is that it’s a much more fuller sounding, more dynamic and more detailed player vs. the 840. I immediately noticed some details in my reference music that I had not noticed before. The 851 also seems to sound better with my interconnects… Harmonic Tech pro silway II. I was initially beginning to wonder if the silway II’s were a little too lean and detailed for the 840; which they still may be. I will continue to update as I get more listening time under my belt. 

The 508.24 was Stereophile A, and one of the finest players I’ve owned. But it’s ancient by today’s standards. 

i had a meridian 508-24 for several years way back then, it is a good unit

then when dan wright made his first modded sony cdp's with tube rectification and output stage, i got that one, and played it against the 508 - it wasn't close... dan's unit made the meridian sound unrefined and overtly digital in comparison