"The next biggest amount of material I have is of the great Chillean pianist Claudio Arrau. Sadly I doubt if we will ever see their like again."Claudio Arrau with Staatskapelle Dresden, Beethoven’s 5th piano concert. It does not get any better than that. I have ony 15 versions to compare, though.
Otherwise,
Gustav Mahler (far from my favorite one) 37
Kris Kristofferson 27 (not counting duplicates in multiple, or even same, format)
The Rolling Stones 47 (including 4 different versions of Exile on the Main Street which I do not particularly like)
Bob Dylan 50 (not including 2 versions of Blonde on Blonde on SACD and Blood on the Tracks cassette, LP, CD, SACD, and Mini Disc, missing 8-track)
Leonard Cohen everything on CD, remastered CD, one single (small size) CD, and LPs (two LP versions each of the older ones and one each of last 5, or so, albums)
I actually like disco.