Geez, they are all masterpieces...MAYH though, yes, is incredibly dark and spectacular. April Ethereal and When are brilliant...The Amen Corners middle section is one of the album's finest moments.
All I can say is, Deliverance is probably the least favourite of the 7, but dammit, what does that really say since I'd give that one around like a 9/10 or whatever. Opeth is just too damn good...