Keith Jarrett hums too, and like him also.
I agree for many of the above mentioned but i would add Jim Kerr who just makes meaninless words from vowels just to fit in the pattern.
Ozzy does not have a great voice but is mostly enjoyable (Sabbath period), as is Iggy Pop, Neil Young, Brian Johnson, Joey Ramone, Anthony Keidis, ...
Of course i am not enjoying Yoko.