I have a fondness for Gospelaccordingto..... - the quintessential "commercially disastrous experimental concept album"

it's been mentioned in a few magazines as an underrated lost classic.
I actually bought it around 1994 or so because of Bass Player magazine's "unsung heroes" article listing this album as an example of JJ's playing (I had Rattus, Black & white, No more heroes + Feline already)
Hugh Cornwell's "song stories" book has some great stuff about the making of this album- eg. "Manna machine" sounding like a large freezer with food inside.