Bad Mixing and/or Mastering

[frisky]

I was thinking about the great accomplishments in engineering and mastering of the 70's (Rumors, Aja, Dark Side of...), and yet I wonder what are the failures? In other words, LP's that were very poorly mixed and/or mastered. And I know that I should be careful not to combine mixing and mastering, as if they're the same thing, which I know they aren't. But, maybe some of you can clarify the distinction. Or, to take it even further... recordings that were (apparently) well mixed, but poorly mastered. And vice versa.

I know this is a very subjective can-of-worms, but I'm curious what the opinions are.