What is the best sounding vinyl?

Any of the Reference Recordings albums, mostly they are jazz. The dynamics are so much superior to the average LP that you keep having to re-set your attenuator to either protect your speakers from the transients or to fully appreciate the pianissimo passages.  Also the sense of hall ambience is unsurpassed.

This is a question akin to:

What is the best food?

The answer depends upon how you derive a rating and what you like. For instance:

Are you referencing recording quality. How you even define recording quality. The style of music, because popular music is recorded much differently than Classical for example. Do you prefer simply recorded live music with the goal of preserving the natural sound of what is being recorded. Or do you prefer masterful manipulated popular music with all of its effects and shaping of the natural sounds?

One approach suits one style of music but not the other. Until we know which stream of music you gravitate to, it is difficult to define 'good' let alone 'best'.

Sheffield Labs Direct to Disc are the gold standard for what can be put on LP's. Too bad there are so few of them.

theophile, For the recotd, I am referring to Reference Recordings, in capital letters, with reference to a specific studio that issued LPs under that brand name (RR) for a brief period of time, mostly jazz. I think the engineer was a Dr Johnson.  I own 3-4 of them.  They click every box you list, except of course their product does not span a wide variety of musical genres. 

Umbrella - Canadian label

Sheffield - mentioned above

Lyn Stanley - female vocalist - 45 rpm D2D - WOW

Analogue Productions has done a lot of 33 and 45 rpm reissues - excellent sound and music

Classical - Original Source from Deutche Gramophone and Pure Analogue from Decca