More so than something like Top 5 Albums, I find this impossible.
Unlike albums, which somehow do, for me, have a personal rating that more or less sticks (at least week to week, if not decade to decade), the idea of rating any of the artists listed in the 70 posts above as being better or worse than any of the others is meaningless.*
So I’ll just mention one or two not already listed (apologies if I missed them)...
Christine McVi
Joan Armatrading
Haley Williams
Goldfrapp
Debbie Harry
*with very few exceptions, I like all of the artists listed.