#4 Aleister Black
Black has it in him to become a top babyface. He recently went over Johny Gargano at NXT Takeover Wargames 2, and thus, in the process has done pretty much of everything one can in NXT. A great way to push him would be to make him win the Rumble match on his main roster debut and then go on to feud with Daniel Bryan over the WWE Championship.
This feud would be a delight for all the independent style wrestlers, who would get to see two of their icons go head to head under the almighty banner of WWE. This would be a great step to fill the void of fresh talent in Smackdown's roster.
Check out which wrestler EC3 finds cute RIGHT HERE
Also, considering how WWE loves to surprise the fans, this may be a viable option. If there is a guy from NXT who deserves to be in this position, it has to be Aleister.