#3 Asuka
Throughout the history of wrestling, there have been some incredibly impressive streaks: The Undertaker's WrestleMania streak, Goldberg's WCW run, and some not so good like Curt Hawkins recent streak, but none of them were longer or more impressive than the run of Asuka down in NXT. For over 500 days, Asuka remained undefeated, and while she didn't give an incoming star the rub of finally ending that winning streak, Asuka's reign will likely never be beaten (winning streak that is, her title reign was topped by Pete Dunne).
On the night that she had to relinquish her Championship due to injury, NXT's GM William Regal called The Empress of Tomorrow "one of the greatest champions in WWE history", and when you look back on it, you can't argue, solidifying her place upon this list. You can put her above one of the next 2 performers on this list if you wish, but a lot of her reign was overshadowed by the next man on our list and other performers, but either way, she's an icon in NXT history, and someone that every woman coming through should aspire to be.