#2 Goldust
Much like his brother Cody, Goldust had a surprisingly big impact when he left the WWF.
Joining the WWF in 1995, the Golden One was one of the company's most dedicated mid-carders and used his years of experience to help build the mid-card scene.
So when he left for WCW, the WWF surely suffered over the loss of one of their most competent hands, as the company was in a war with the Atlanta promotion.
Perhaps the biggest and most direct impact Goldust's departure had, was on GTV.
For those younger fans, GTV would show candid footage of Superstars, often in compromising states, to shock both fans and Superstars, as speculation ran roughshod of who was behind the camera.
The plan was supposed to be Goldust (as in Goldust TV), but once he left, no other solution was offered, and GTV remains a mystery.