1. Oprah Winfrey
2. J.K. Rowling
3. Martha Stewart
4. Madonna
5. Celine Dion
6. Mariah Carey
7. Janet Jackson
8. Julia Roberts
9. Jennifer Lopez
10. Jennifer Aniston
11. The Olsen Twins
12. Britney Spears
13. Judge Judy
14. Sandra Bullock
15. Cameron Diaz
16. Gisele Bundchen
17. Ellen DeGeneres
18. Nicole Kidman
19. Christina Aguilera
20. Renee Zellweger

Of course, the celebrities with the longest careers proved the most daunting to evaluate. Since beginning her career in the early 1980s, Madonna has sold some 200 million albums worldwide and starred in a string of largely disappointing films. She owns an impressive portfolio of properties and briefly ran her own record label, Maverick, a part of Warner Music Group. Our estimate of her net worth--$325 million--is definitely on the conservative side.
Forbes' list of the 20 Richest Women in Entertainment is the subject of a one-hour special slated to air on the E! Entertainment Channel on Jan. 20. Check your local listings.

Madonna

Rank: 4
Net Worth (in $ millions): 325
Age: 48
Marital Status: married
Kids: 3
Source: music

She could have easily disappeared into pop obscurity like the other frothy pop tartlets (Cyndi Lauper, Neneh Cherry) who came to fame on nascent MTV in the early 1980s. But Madonna's masterful manipulation of her image and the press, combined with an astute business sense, have crowned her as one of entertainment's wealthiest and most enduring acts. While her albums don't sell like they used to, her concerts still set attendance records all over the world, grossing $1 billion over the course of her 20-year career. The Material Girl's portfolio is also crammed with expensive items like contemporary art, real estate and a wardrobe of no small historical significance.