I'd like to be able to say Appetite for Destruction by G'n'R, but it has more than one weak song in my opinion. Same goes for Master of Puppets by Metallica and Back in Black or Highway to Hell by AC/DC.
I think that Thank You by Canterbury is one of the greatest albums I've listened to, simply because in my opinion there isn't a weak song on there. This isn't to say that any one of the individual songs matches the greatness of the classics, but the album as a whole is brilliant.