10. Goldust
Goldust underwent shoulder surgery in December 2010, and he's been working as a backstage agent since then.
But he's still considered a member of the active roster, and he would be a great fit on SmackDown.
Despite his ridiculous gimmick, Goldust is one of the better pure wrestlers in all of the WWE, and he's never really going to be used in a very prominent role on Raw.
At this point in his career, he should be used to help others improve in the ring, and that's exactly what he could do on Friday nights. Goldust would be a great addition to the mid-card as someone who would assist younger wrestlers in developing their skill sets, while simultaneously putting on very good TV matches.
Feuds with some of the blue brand's mid-card heels—even Cody Rhodes perhaps—could result in what SmackDown's known best for: Quality wrestling.