#1. Goldberg
Many would argue that Goldberg has done enough to cement his legacy and that his last three matches weren't necessary. Since his 2018 induction into the WWE Hall of Fame, he's had four matches - against The Undertaker, Dolph Ziggler, 'The Fiend' Bray Wyatt, and Braun Strowman.
He's won two out of the last four, with many criticizing the decision to have Goldberg beat 'The Fiend' to win the Universal Championship. Either way, he put Braun Strowman over at WrestleMania 36 and will likely be away from WWE TV for a while. There's a higher chance of him getting a warmer reception if he's in a non-title feud - and he's certainly big enough where he doesn't need one.
However, we realize that he's offered big-money contracts to appear and at the end of the day, he's a bigger draw than almost all of the WWE roster.
If he is to return, a year away from TV would do him good. It would give him a chance to rest as well as return for a more exciting program.