#1 Trevor Lee

In the past, WWE have stayed away from former TNA/Impact stars, but with the birth of NXT, they've become a valuable source for the company. The latest big name to come from Impact is the Carolina Caveman, Trevor Lee.
Like most working on the indies today, Lee's in-ring skill-set is incredible, with several of the most innovative moves in wrestling today. He blends this all with great character work, making him a future NXT Champion for sure.
Unlike others on this list, Lee doesn't have to change much about his game to become NXT ready, and given that he's competed against most of the current NXT roster already, WWE just need to bring him to TV straight away.
Trevor is already announced for Progress Wrestling's Super Strong Style 16, a tournament they sent Kassius Ohno to last year. Thus, it's clear they've got big plans for him, and given all of the tools that he has, they should just throw him straight in the deep end.