Very best sounding Vinyl

Norah Jones as mentioned 
Walter Susskind conducting the London Philharmonic Crystal clear direct to disc everything you would want in a classical record.
Charlie's Byrd Crystal clear also d2d the drums are in the room.
The Band brown LP 45 rpm
I use these to demo my system.

@fjn04 -Bloody Sabbath was not released on Vertigo but their first album on the WWA label- the first four albums were on Vertigo and the cheap trick was to find those earlier albums on the WWA label bearing the Vertigo matrices that had been crossed out but used the Vertigo metal parts. Sabbath was my entry point into the Vertigo catalog which has some wonderful, obscure and well recorded prog rock.

I would recommend old mfsl vinyl, preferably mastered by Stan Ricker.  

For analog recordings the general rule is to find pressings from the home country of the label in question. The golden age for analog sound was late '50s to mid '60s. So for classical recordings from Decca or EMI get UK pressings, for RCA or Mercury get US pressings. For American jazz get US pressings (blue note, Prestige, Riverside et al). The earlier the pressing, the better the sound.

From the late '60s multi tracking became the norm, which changed the game with new engineering and production challenges. Some labels were more succesful than others in creating great sonics. Still, for British rock get UK pressings, for US rock, well you get the idea.

The most likely explanation is all record companies kept their original master tape and sent copy tapes to other countries. This quality step down at the source is elementary and can never be undone, no matter how good the engineering.

During many years of collecting vinyl records I've discovered that pressings which seem to be identical can differ greatly in sound. In some cases the matrix info on the deadwax with stamper codes and such can help explain these differences (the earlier the lacquer, mother and stamper, the better the sound). But many labels don't offer this kind of info, in which case comparative listening is your only option. This requires multiple copies (preferably in EX or NM condition), which is time consuming and costly.

This situation has created the business model of Better Records, who do all this work for you. I've never bought anything from them, but I'll bet their hot stampers are early copies from the country of origin. 

I guess I should say that in theory the Better Records business model could work,never having bought one and never likely too it's hard to be sure.

Just for myself I would derive little pleasure from the knowledge of having spent $400 on just one record....ever.
It would seriously outweigh any possible SQ uptick and would do a number on my mind that would never relent.

Just my 2 cents