[WorthlessLiar]

Protoclown, a concept album is when the album tells a story or at least has a consistent lyrical theme (at least I think so). I'd classify some of these loosely as concept albums but I'll list them anyway.

Opeth - Still Life
Blind Guardian - Nightfall in Middle Earth

and the non-metal concept albums (because it seems wrong to list Opeth with Weezer).

Snapcase - End Transmission
Radiohead - Kid A
Weezer - Pinkerton
Hum - You'd Prefer an Astronaut