worst sounding great lps

I agree and think it's sad that Derek and the Dominoes, Born to Run, and Exile are not great sounding.  Each of these sounds muddy and veiled to me.  

I disagree on Queen.  Most of their stuff was superbly recorded--at least to my ears. 

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?