#1 Andrade 'Cien' Almas
Andrade 'Cien' Almas is quickly rising up the ranks on SmackDown Live currently. He has a feisty manager with him in Zelina Vega, who provides the soundtrack to the carnage El Idolo brings. I personally think that he is a great opponent for Roman Reigns. After all, he's one of the best performers in the world right now.
The two men have never had a chance to square off, considering they're on two different brands. I can see them clashing when the time is right. Hopefully, by then, Almas will be a top-level competitor.
I know I left Shinsuke Nakamura off this list, but the two men had a lengthy sequence at the Royal Rumble this year. I also left The Rock out, because he's not a full-time WWE performer.
Let me know whom you'd like to see Reigns square off with, for the very first time, folks!