#1 Batista

Much like the Dudley Boyz, Batista's most recent return to the company didn't exactly go to plan.
Being pushed as the company's big star (over Daniel Bryan), Batista was rejected by the fans, though the company soldiered on, having the Animal win the 2014 Royal Rumble.
In interviews, Batista has said he does want to return to have a final good run with the company, and hopes this will come in 2019.
Whilst there was a rumored Batista-Triple H match for WrestleMania 35, (which was hinted at on SmackDown 1,000) this is now up in the air, given the Game's torn pectoral injury he suffered at Crown Jewel.
Even if he wasn't to face the King of Kings, there's no shortage of Superstars that the Guardians of the Galaxy star could feud with, though the WWE would have to be careful to avoid a repeat of 2014.