A lot depends on how you define hard rock and metal. As for me I have to say Led Zeppelin but there are a lot of other hard rock bands that I like. Zeppelin was defined as metal back in their heyday but I think now the term mostly applies to 80's bands like Metallica and Gun's 'n Roses.
You did say album so I have to say Led Zeppelin I and Led Zeppelin II. Who's Next was a great one too.
Mouth for War. The impact on the era trumps a significant amount of anything in the genre regardless of era. Don't think it stands against all time, but the shelf is pretty tall.
Y'all are gonna think I'm crazy but album for me is Operation Mindcrime by Queensryche. The entire album is a concept album that tells a story and rocks the whole way through.
Mindcrime is and still is, the absolute shit. But being a concept album, IMO, takes it down a notch when compared to all time. Guess cause its a long story as opposed to a group of short stories, but thats me. Geoff Tate though, dudes got some serious pipes.
You know man, I think that's what makes it great, how many artists have ever succeeded in making a concept album where the story really doesn't even matter? You can listen to that album and the story is awesome but you don't have to be aware of it.
You're from my Dad's era I bet, (nothing wrong with that, in fact I bet it was awesome) you were born late 50's or early 60's weren't you? I never cared for The Who but I do recognize they were a great band.
I agree because of this particular album. The story fits the genre better than any other concept album. I just think it's easier to write a concept album than it is an album that can cover more spectrums. The Wall is a rare takeaway for its complexity. Even the story was complex