worst sounding great lps

Anything on Roulette, and sadly they had some great artists in their stable at various times, including Mel Torme', Sarah Vaughn, etc.

Anyone who thinks the Black Sabbath LP's are mud, most likely has NOT heard the original UK Vertigo pressings. IMO, these are some of the best rock recordings available. Comparing to the later US reissues is simply doing them an injustice! 
Personally, i think some of the Santana LP's could be so much better recorded. The potential is there, but the original tape masters must have left a lot on the cutting table. The new MFSL Abraxas 'one step' must be interesting, because IMHO the original master probably wasn't that great to begin with...so why pick this LP to start your series; unless you wanted something that had wide appeal! ( But not great SQ to start with....???)

Needs to be qualified: original versus reissue, country, label. For example, "Are You Experienced" sounds great on an original British pressing, not so great on the American version.

Iggy- Raw Power: The Bowie mix is underrated- sounds great to me.

Springsteen- Born to Run- originals sound poorly mixed and recorded to my ears.

Fresh Cream.  Ugh!  But what a great album.

+1 on Layla--jeez, what were they thinking?

Is the original US edition (Reprise?) of Hendrix´s  Axis any good ? The UK reissue (Polydor) from 1983 is too trebly /peaky to me.
As the original UK editions of "Electric Ladyland" go for astronomical prices, what later editions (UK or others) would you recommend ? Thanks in advance.