Here's a GOAT women ranking which I came across on another message board, which I found to be very interesting.
I think the reason why Australian Tennis Great Margaret Court was excluded by the maker of this list is because she won 13 of her 24 slams (a record btw) before the Open Era. If Court was included, she would easily been #2 or #3 on this list but I still agree on how the greats were ranked.
Here's the Greatest of all time (Open Era)
1. Martina Navratilova
Simply the all around greatest athlete and icon of the women's game. Her Grand Slam titles (in all formats) make her the best, and what she did as far as introducing power-training into ALL of women's sport cannot be duplicated. The best.
2. Chris Evert
The most consistent player in Open history (men or women), tied at 18 Slam singles titles with Navratilova, a career 90% win-loss record (greatest of men or women), longest surface win streak of any player (125 clay wins), and winner of at least one Slam title a year for 13 straight years. Seven-time year-end No. 1 player. Greatest clay court artist of all time (7 French crowns). Though Evert was not a truly great athlete, she was a ruthless court tactician--much greater than Hingis. Though Billie Jean King gave women's tennis its great foundation, it was Evert who brought worldwide popularity to the game with both her phenomenal success and her feminine appeal. A superstar who was, in her day, far more popular and light years more accomplished than any Kournikova.
3. Billie Jean King
Her many Grand Slam titles are perhaps rightly overshadowed by her power as an ambassador for the game--she made women's pro tennis POSSIBLE and was was one of the all-time fiercest competitors. A pure force of sport--PERIOD.
4. Steffi Graf*
Graf won more Slam singles titles than any other woman in the Open era and is the only winner of the Calendar Slam in the Open era. However, note the asterisk. Her great accomplishments will always be balanced by the reality that her reign had come to a complete end at the hands of her greatest rival and superior--Monica Seles. When Seles was stabbed, Graf's post-1993 accomplishments lose a luster that will never be regained. Even so, Graf belongs at No. 4.
5. Monica Seles*
Seles could well have ended up No. 1 if she had not been nearly murdered on court by a fanatic. By far the most relentless, powerful, and determined player women's Open Era tennis had ever seen, she was cut down before her peak, but in just three years time had racked up 8 Grand Slam singles titles, beginning with the 90 French in June and ending with the 93 Aussie in January. In the process, she utterly and unexpectedly dethroned the great Graf--no contest. She braved everything to come back after a three-year hiatus to add one last Slam in 96, bringing her total to 9 for the Open era (Third behind Graf and Navratilova/Evert). Seles was simply the greatest competitor and power the game had ever seen in her peak years. There should have been many more Slams (and would have been), but we must never forget that it was NOT a "tennis injury" or "accident" that took her out. It was a calculated, deliberate act of human CRIME. Her legacy will live on.
6. Serena Williams
Powerful and explosive, Williams, too, could have attained the NO. 1 spot on the list. However, no crime took Serena from the top; she lost interest in being the best. Nevertheless, Serena Williams easily rates the Open era sixth spot for her dominance (7 Slam titles) and being the only member of the post-99 "new guard" to hold all four Slam crowns. Amazing champ.
7. Martina Hingis
At five Slam titles and a stunning record in doubles and regular tour events, Hingis is indeed one of the all-timers. Never a power player but an Evert-like clinician, Hingis made an indelible mark on the game, and her 2006 comeback to the Top 10 after three years only adds to her legacy.
8. Venus Williams
Tied with Hingis at five Slam titles, Venus is perhaps the player who has most underachieved of the Top 10. More gifted athletically at the net and possessed of an even better all-around game than her sister, Venus lacked the sustaining drive to continually dominate. A brilliant athlete, an accomplished champion, but she could have won more titles with a little more fire in her belly.
9. Justine Henin-Hardenne
Five titles. A spotless, technically beautiful game. Grit that is second only to Seles and Serena Williams, Henin-Hardenne (despite bouts of poor sportsmanship) is undenied as one of the best of the truly "Open" era.
10. TIE-- Jennifer Capriati and Lindsay Davenport
A teenage phenom tennis-machine, Capriati could always hit with the best of the power players from the start. When all seemed lost after her 93 flame-out, Capriati returned to not only rack-up 3 Slams, but to claim the No.1 ranking. In a similar way, Lindsay Davenport, who was never expected to break through to the top, completely transformed her fitness to the astonishment of all and nailed three Slams of her own, as well as the top ranking. Two champions who actually made the most of very "iffy" career situations to achieve greatness.
Arantxa Sanchez-Vicario--Close to a three-way tie with Capriati and Davenport, Sanchez-Vicario's 4 Slams are offset only by her inability to consistently challenge Seles and Graf on other surfaces. Still, she's one of the all-time greats and an icon of stubborn, dogged tennis play.
Tracy Austin--Two Slams, a few year-end WTA championships, the No. 1 ranking, and a player who scared both Navratilova and Evert during their heyday. A mental/physical burn-out derailed this phenom's otherwise remarkable career.
Amelie Mauresmo and Maria Sharapova--Currently tied for actual greatness, Mauresmo conquered two Slams as her career winds down, while Sharapova is still just beginning. Look for Sharapova to ride into the Top Ten within a few years. Mauresmo may have shot her wad.
Gabriel Sabatini and Mary Pierce--Though Pierce has two Slams and Sabatini one, Sabatini was the player with more overall impact. Sabatini's only sorrow is that she peaked during the Seles-Graf war and could not make much of a dent in either of their games at the Slams.
Jana Novotna and Iva Majoli--One Slam Wonders, yes, but Novotna, especially, made an enormous impact on the tour in a long and only twilight "fulfilled" career.