9. Heath Slater - 10 Years
Heath Slater signed his WWE contract in 2006, reporting to developmental for a few years before emerging as one of the breakout stars on the first season of NXT. He was then key to the big Nexus push on Raw, and has remained a main roster personality in the six years since. However, despite his years of experience, Slater isn't really perceived as a WWE stalwart; when he has been used, it is mainly as a jobber. That perception has made his WWE career come off as irrelevant and meaningless, when in truth his tenure ranks as one of the longest. In contrast, Kevin Owens has been signed for only two years... in which time he has already won two more singles WWE Championships than Slater's zero.