Who was the best girl group?

Diana Ross and The Supremes

The Supremes were the most successful if you take into account the name changes.

banarama...........................................

Bangles, Dixie Chicks

The most successful is the Spice Girls, 85 million sales.
destiny's Child had sales of 65 million.
https://en.wikipedia.org/wiki/List_of_best-selling_girl_groups

I have no idea who 3LW were.


Wiki says the Andrew Sisters from the 1940s was actually the most successful with sales of about 90 million units or perhaps the Supremes from the 1960s too.

 extract.
Accurate total sales of the Supremes records are unknown – estimates range from 20 million records up to 100 million records.
The group Andrew Sisters is not on the listed because none of their records were certified by organisations that represent the music industry, although their estimate sales are 90 million copies worldwide

And the most successful song of all-time  by a girl group is The Ketchup Song by Las Ketchup. 7 million sales.
https://www.youtube.com/watch?v=AMT698ArSfQ

the most successful album by a girl group is Spice by The spice Girls.
https://en.wikipedia.org/wiki/Spice_(album)

The Bangles,  

The supremes, from the 1960's.

The Supremes.    With or without Diana Ross as the name above the title.

I'm a big Joan Jett and the Blackhearts guy. Why? Because "I LOVE ROCK N ROLL".

Suede or Culture Club.