Although not my cup of tea, I'd have to nominate Dark Side of the Moon for this thread. And also OK Computer. Both 'complete' albums.
Both the first two Suede albums deserve consideration, particularly Dog Man Star. And maybe Closer by Joy Division.
I think a lot of people have misinterpreted this thread. It's not just about favourite albums. It's about albums without a single duff track. Quite rare in my experience. I mean, for everyone who's said Revolver - what about Yellow Submarine? It's just awful.