#3 Gail Kim

You couldn't ask for a better start to a career in the WWE than Gail Kim. In her very first match with the company, Kim won a Seven-Diva Over the Top Rope Battle Royal to win the WWE Women's Championship. It was pretty much downhill from there on out. Less than a month later Kim dropped the Title to Molly Holly, and was soon sidelined with a broken collarbone. About 6 months after returning from the injury, Kim was released in November of 2004.
She would return 4 years later, but her second stint with the WWE was an unpleasant one for Kim. She had a few opportunities to recapture the Women's Championship and later the Divas Championship, but was never victorious. By 2011 Kim wasn't being featured as an in ring competitor as much. She did serve as the valet and on screen love interest of Daniel Bryan for a time, before ultimately leaving the company.
Female superstar says she inspired John Cena turning heel HERE
On an episode of Monday Night RAW in August, Kim participated in a battle royal to determine the number one contender for the Divas Championship. She was told to get eliminated within a minute of the match starting, and choose to just eliminate herself. She would never wrestle for the WWE again.

Since her release, Kim has never been shy to express her feelings about her time in the WWE. Saying the company was holding back female talent by constantly booking multi-women tag matches that had no direction from a story line stand point. She told the Fightful Network last year, that eventually she became so unhappy she had to leave. Recently Kim has been more complimentary of the booking of the WWE women's division, particularly on NXT.
Kim has done very well for herself outside of the WWE, winning a record 7 Knockout Championships while in Impact Wrestling. That said, you have to wonder if things would have been different for Kim had her career began today. It's no guarantee her time would have been more enjoyable, but one would have to think she'd have more opportunities.