#4 Bayley

Bayley was a huge success in NXT. Her initial run in Raw was very much appreciated, but lately her character has become stale. Her character is hugely famous among the children and women, but she needs to garner the attention of other members of the WWE Universe. Her hug-o-nomics isn't currently working in WWE. It's not that Bayley isn't an accomplished wrestler; her matches against Asuka, Becky Lynch and Charlotte were amazing in NXT, and her match with Sasha Banks at Takeover:Brooklyn was one of the finest in WWE history.
NXT viewership is much smaller than Raw or Smackdown and some wrestlers do tend to perform better on the smaller stage. Her run as a heel might be entertaining; she can show her frustration of not being accepted in RAW since her debut.
Bayley's character is getting stale, and she definitely needs a push for her character to grow.