I would agree on the smiths I don't think any of their LPs are average or bad, each one is top, but then I could say that of elbow, who I am sure will not appear here.
On this poll up to now I can only think of the Pixies, Pulp and James that have consistently produced LPs that are both top drawer and improve each time in their peak years, from my time growing up in the 80s/90s.
As a child born in 76 tge 70s stuff is only from reflective listening and if I had to say put of the likes of the gratfull dead, steeley dan etc I prefered The Band if honest.
Again though having heard all their LPs Zeplin are the great pretenders and an average band that done good.