Even The Devil you Know beats the shit out of Technical Ecstasy and Never say Die... I'll go further saying that Dio Sabbath, Tyr and Headless Cross are even better than Sabotage. Also, Ozzy is the least important thing on the quality of the first Sabbath albums.
About Agalloch, while I understand what people see on their music, I've never been a fan of it. Pale Folklore was the first thing I heard of them in the late 90's and it sounded pretty much like a lighter Bergtatt (In fact, I used to say that Agalloch = early Ulver + Empyrium). What came after was kinda better but, for example, the vocals has been always bad IMO. Marrow sounds like shit and Faustian is another subpar effort. Well, It's noticeable the huge difference in quality from their full lenghts to their ep's. The grey, Tomorrow will never come and Faustian are very mediocre compared to the full albums too.
Some things that I think Agalloch lost just after Pale Folklore (The Mantle, Ashes) were the dynamics and intensity. Like Drudkh, they got a 'formula' of post-rock/black stuff that is usually pleasing to both the metalheads and people getting into it (especially the latter, like Fen or Alcest), releasing some stuff that was too similar. Both Mantle and Ashes suffer from this, since the songs on those albums are very, very similar to each other and since the mood and intensity it's also the same, those albums feels like a one continuous (and boring sometimes) song, developing the same ideas over and over (The Mantle has 1 good song tho, being I am The Wooden Doors).
I know this won't be shared by so much, since the Agalloch fanbase is pretty rabid, but anyway.
Last thing about Metallica: RTL is a way better album than MoP, not just the songs are better, but the album as a whole feels more coherent.
Not that controversial IMO, but Woods of Ypres was from start to finish a piece of shit, including the last album (5). The lyrics of many songs are incredibly laughable too.
Another 'controversial' thing: Opeth live nowadays it's fucking boring.