I was trying to come up with any band that had ever challenged the amazing string of incredible albums put out by the BEATLES in their best days wherein they released 6 back-to-back great albums:
RUBBER SOUL
REVOLVER
SGT. PEPPER'S
MAGICAL MYSTERY TOUR
WHITE (68)
ABBEY ROAD

I realize one could argue over MMT as well as Yesterday & Today and Yellow Submarine. Those were released, perhaps, for ulterior purposes.

At any rate, the only other band that I could come up with that rivaled the amazing amount of writing and performing talent that could release 6 back-to-back albums that kept my interest was YES (I am showing my bias here?)
THE YES ALBUM
FRAGILE
CLOSE TO THE EDGE
TALES FROM TOPOGRAPHIC OCEANS
RELAYER
GOING FOR THE ONE