#2 Andrade

Judging by the way he's been booked recently by the WWE, the Mexican should be a big player in 2019. Andrade has proved time and again, that he is one hell of a performer, maybe even the best on the SmackDown roster. This year should be his year to shine.
His on-screen pairing with Zelina Vega, which has been a hit ever since his days in NXT, gives his character a bit of an edge. His matches with main event stars like AJ Styles and Daniel Bryan have given him a chance to impress backstage officials. Also, apparent rumours of Andrade impressing Vince with his matches on SmackDown were gaining a lot of interest among fans.
All these factors led to Andrade receiving a push from the management and it was evident at this year's Men's Royal Rumble match, in which he was among the final four members. That was a bold move by WWE, and certainly, one that should boost his position on the main roster.
A feud that has been building steam on SmackDown Live over recent months, is that of Rey Mysterio and Andrade. Mysterio will definitely be the perfect opponent to help elevate Andrade to become a bonafide top-tier talent and the next big Latin superstar Vince McMahon always wanted.
Even if their feud fails to make it all the way to Wrestlemania, Andrade at least deserves to be in the mix for the United States Championship, a title program that desperately needs a better feud and a worthy superstar to hold the belt.