#3 Kenny Omega

At time of writing (January 9 2019), Kenny Omega had still not been confirmed as a member of the AEW roster.
What he has done is confirm that he will no longer be competing for New Japan, following his loss of the IWGP Championship at Wrestle Kingdom 13 to Hiroshi Tanahashi.
Rumours had circulated that Omega was WWE bound, but it now appears that Omega will join his Elite buddies in AEW.
Should he do so, then he would be the biggest star in the promotion. Unquestionably the best wrestler on the planet right now, the 35 year old Canadian is the obvious choice to be the very first AEW Champion, if he signs in time to win the title.
However, his New Japan run showed that Omega's greatest strength was in the chase of the title, as it took him over 18 months to win the big one, and the crowd were at fever pitch when he finally did so at Dominion 6.9 in July 2018.
Omega's time might have to wait.