#1 Paulo Dybala
Well, it is really funny when you look at it, that Coutinho left Liverpool to win Champions League and actually, Liverpool ended up winning it a season later. But trolls and fun apart, Liverpool have serious creativity issues in their team.
The reason Liverpool are so dominant is due to their aggressive full-backs and their ruthless front-three. The midfield plays little or no role in goalscoring as it seems. None of the midfield players is a regular in the team and Klopp hasn't been successful in finding go-to combinations.
So, until or unless Liverpool gets some creativity in there, teams would notice this flaw and outnumber the midfield where they largely lack creativity. Who better to sprinkle some creativity in their than Paulo Dybala? The Argentine is a proper playmaker and a genuinely good dribbler. He is reportedly looking to leave Juventus and what better destination than the Anfield.
Dybala can play his #10 role freely, without competition, because ever since Coutinho left there is no one playing in that spot. Him as the creator through the middle, the fullbacks surging forward, with a dangerous front-three, that is a horrific imagination for defenders.