What do you think is the best sounding metal album

Another vote for Puppy here; industrial emerged out of the metal backwater and Puppy invented it (nods also to Einsterzende Neubaten) Also saw them for Last Rights and Greater Wrong.. tours.

But also:

Tool - any recording
Type O Negative - October Rust
Agalloch - any
Tiamat - Skeleton Skeletron
Moonspell - any
Theatre of Tragedy - Aegis
Black Sabbath - Sabotage (especially remastered on vinyl)