Ok, I'm going to take a crack at this, but base my list mainly on overall ability and impact on the state of women's wrestling. Thus, I will not include Sunny since she was not an active competitor. Let's see what we can come up with.
1. Fabulous Moolah - The longest reigning women's champ and was somehow still relevant until her death. When you are in your 70s and still important, that's impressive.
2. Sable - I know some of you didn't have her very high, but this woman brought back women's wrestling. It was defunct after Alundra Blaze left and the new division was created for her. She was tough and sexy and the Sable bomb was lethal. The modern diva was and is based around this woman.
3. Chyna - Perhaps she could be higher due to her impact AS a woman, but in terms of being a part of the women's division, that came later. She was just that much better than everyone. This type of woman transcends labels and was just a force to be reckoned with.
4. Wendi Richter - She actually main evented during the Hulk Hogan era. That should tell you enough about her impact on women's wrestling. As part of the Rock n Wrestling connection, she helped wrestling go mainstream along with Cyndi Lauper. On top of that, she was a solid in ring talent for her time, but it's her impact on exposing women's wrestling that lands here at this spot.
5. Lita - This might even be a little high, but admittedly I enjoy her work. She mixed it up with the boys in a time where only Chyne really did and she did it well. She made it ok for women like Eve Torres today to be flipping around a ring, doing moonsaults and the like. She was fearless and brought a high flying excitement to women's wrestling that hadn't been seen before.
6. Alundra Blaze - Probably the premier women's wrestler of the early 90s, she worked well with all types of opponents. Her stunt when going to Nitro is legendary, and it removed women's wrestling from WWF programming for 4 years. That type of impact can't be overlooked. She really started the friction between WCW and WWF in a sense. That's big time.
7. Sensational Sherri - One of the premier managers of all time, she also mixed it up in the ring some. Her high ranking is due to having an impact on a ton of careers and showing that managers could evolve into wrestlers. That trend certainly grew as we got into the new millennium.
8. Jacqueline - A fine worker in the late 90s and the new millennium, she was the first women's champ when the title was reactivated, getting that distinction over Sable. What is important about this is that she was the first African American women's champ, making her the first African American to hold a major title (meaning highest title for a particular gender). I think that's major, as it opened up the possibility for other minority women to make an impact on the division. Plus, her feud with Sable was one of the hottest stories of 1998, the year of Austin. That's impressive stuff.
9. Ivory - In an era where fake breasts and a model look usually determined success, this woman made her mark on merits alone. An excellent in ring competitor (perhaps the best technical worker I've ever seen from a woman), she won the title 3 times and was dominant while a member of the Right to Censor. This group allowed her to showcase her abilities outside the realm of gimmick matches which were popular at the time. Truly an excellent talent in the ring.
10. Mickie James - Another excellent ring talent, she debuted huge by taking down crowd favorite Trish Stratus and winning over the crowd due to her own talents. She went on to consistently be in the title hunt and is one of the most popular Divas of the last 7 years.
11. Trish Stratus - Surprised she's this low? Actually, I was going to put her lower. For the first few years of her career, she was a valet and occasional wrestler (though untrained at the time). During that time, her work in the ring was downright embarrassing. Credit her though for improving, as she did become more of a force as time went on. This woman is probably as infamous as she is due to her beauty and refusal to pose in Playboy. Her legacy is quite inflated given she was in the business for 6 years and more than half were spent as a valet, but she provided a foil for Lita and took good bumps for her, so that's important for that time period.
12. Mae Young - While she probably gained more fame as an old lady, more people could probably name her today than most women in wrestling. That fact alone lands her on this list, but if you go back and watch her matches from many years ago, she wasn't bad. Nowadays, she's pushing 90 and still shows up from time to time. That's impressive. As long as we don't have to see her naked or anything.....
13. Stephanie McMahon - I thought about putting her higher due to her impact on the industry, but since she was never much of a worker like her brother became, she can't get much higher. However, she was the first woman GM of a wrestling program and had a major impact in that regard. I think we all wish that her husband taught her to wrestle a little better for her few performances though.
14. Leilani Kai - Another mid 90s worker, she took the title off of Alundra Blaze. An excellent worker from Japan, her ring work speaks for itself. At that time, looks weren't important, and she was able to put on better matches than most of us are used to today.
15. Beth Phoenix - The Glamazon lands here and no higher due to her career still having a lot left. What makes her unique is her muscular physique but still posessing beauty. She is a better looking Chyna, as she muscles her way through most Divas. Her in ring work is stellar and she has wowed the crowd over the years, recently becomign the second woman to ever enter the Royal Rumble. That's elite company, and she clearly has shown that you can be beautiful and strong and still succeed in woman's wrestling.
16. Rockin' Robin - From the famous Smith wrestling family (her dad is the same as Jake Roberts but different mothers), she was able to work well and actually retired the belt for the first time in 1990 as she left the WWE. She was trained well and certainly did her part to keep women's wrestling going once the likes of Wendi Richter, Moolah, and others were long gone.
17. Michelle McCool - Perhaps one of the best to make the transition from a career outside wrestling, this former teacher has gone from pointless valet to one of the best WWE has to offer. Some might say she has her spot due to her relationship with the Undertaker, but watch her matches and you'll think otherwise. This girl has worked hard to become a force in the ring and it has payed off. Her impact on the industry may not be great, but she can work.
18. Molly Holly - Debuting as part of the Holly family, this woman will be remembered for great matches and for shaving her head. This type of stipulation was more common among male matches, but females generally were protective of their scalps. However, this brave woman was the first to put it on the line. She was a fine worker who, like Ivory, fought the era as a non-model type, and even translated that into an on camera character as a "prude conservative". However, it's her shocking head shave that will be remembered, though if you watch her work in a ring, that part should definitely be remembered too.
19. Victoria - She debuted as an enforcer for Molly Holly and eventually gained her own momentum as a star. She can work and has the distinction shared with Lance Storm for "most famous wrestlers with a widow's peak hairline". While she is not legendary, she was always solid and one of the better ring workers of her time, so she lands at this spot on the list.
20. Bertha Faye - Her unique look will keep her in the minds of wrestling fans forever. An overweight competitor, she was the last person to beat Alundra Blaze in the WWE. Unfortunately, she lost the title back and was largely forgotten. She died in 2001, but will always be remembered as a talented performer who will never be duplicated, mostly due to the image restrictions held to WWE divas today.
Perhaps some new Divas will make this list eventually, but that's what I got for now. I know some of you will disagree with me, but good luck making your own lists. It was fun but it's hard!