What about the live albums. Here, I think they pretty much abandoned any attempt to be creative in any way as they are uniformly dull and unimaginative. In that sense, for me the best of a boring bunch is 3SL. Sure it's pretty uninteresting but its starkness kind of makes a statement about where they were at that time. I really liked the approach of having just one big fuzzy pic. It was a pleasing contrast to the previous live album with its predictable montage/scrapbook style that was ploddingly typical of 70s double live rock albums.
Genesis had a spectacular stage and light show and the album covers reflected that.
I recall walking into a record store in the late 70s and seeing a display island of about a dozen or so albums and my focus lured like a magnet to that image with the cyan blue curtain in the background and that bizarre character standing behind a bass drum in the middle of the stage with that red headpiece and glowing eyes..
Personally, I love that cover.