#1 Apollo Crews
Like the Viking Raiders, Crews doesn't need to work on improving in the ring. He's already one of the most athletic and entertaining stars in the ring. But for some reason, he hasn't been able to connect with the audience. There is a portion of the crowd that cheers for him, myself included, but his matches have usually been met with silence.
Part of that reason might be because of the fact that he doesn't have a defined character. He smiles, is nice and is a great in-ring worker. But other than that, he doesn't have a hook to get the crowd behind him. A move back to NXT would not only offer up an experienced worker with main-roster experience to help the rest of the talent but it would also allow Crews to work on crafting a character.
Working alongside the Velveteen Dream would do wonders for him as would getting to re-watch the process for other stars new to NXT and WWE. Crews is a great talent that has put on some great matches lately including his bout with Andrade and his contest in NXT with Kushida. He just needs a personality and he might be able to find it by going back to the yellow brand. That crowd would definitely also appreciate him more.