Well, I was excluding artists that only have one release, obviously.
I just don't care for the majority of the rest of the catalogs of those artists...that's not to say that everything else in their output is garbage, well maybe with Live, Tiamat and Korn

, but with the others, I consider their "best album" so far and away from anything else they've done that they may as well have not recorded anything else.
I'm dead serious about the Zeppelin and Radiohead, by the way. I'm not that into Zep to begin with, but Zeppelin 1 I can say I actually enjoy.