Who are the Top 5 best selling singers of all time?

The 10 most selling female artists in the world are:

1. Madonna
2. Mariah Carey
3. Celine Dion
4. Whitney Houston
5. Barbara Streisand
6. Britney Spears
7. Janet Jackson
8. Olivia Newton-John
9. Cher
10. Tina Turner

These numbers only include female solo artists.