WCW - Majority of the lower card especially during the Russo and NwO Hogan years. Booker T might have been the only developing rising star WCW managed to create in the late years of the company for the main event division.
WWE - Before returning back to the WWE, Christian would have been an example since in his case Vince was completely against pushing him even though he was popular with the crowd and developing into a future main event star.
Brandon Walker
John Morrison
MVP