#4 SmackDown Women's Champion: Asuka

Asuka, the current SmackDown Women's Champion, won the first ever women's Royal Rumble match at last year's Royal Rumble PPV.
She then went on to challenge the Queen, Charlotte Flair for the SD Women's Championship at WrestleMania 34. Just to remind you all, she went into this match still undefeated in WWE, but her streak was broken by Charlotte as she made her tap out to retain the title.
#3 RAW Women's Champion: Ronda Rousey

Ronda Rousey made her debut in WWE on the same night when Asuka won the Royal Rumble. She immediately went face-to-face with Stephanie McMahon that night as well.
At WrestleMania last year, she teamed up with the Hall of Famer, Kurt Angle to take on the team of Triple H and Stephanie McMahon in a Mixed Tag Team Match.
This was her debut match in WWE, and she impressed fans with her skills and power on the first night itself. The match overall was entertaining, with Ronda and Kurt picking up the win over the Authority.