It would be more interesting if people only brought the name of people they love and listened to the discography with an open mind. It will automatically sound better than if you do it through a bad mental filter.
With that said:
The worst (subjectively, of course):
Kylie
Rihanna
Cher
Christina
The best:
Janet
Mariah
Madonna
Britney
Brandy
Aaliyah
Cyndi
The rest is from people I don't like the music of or simply don't care about.