The big three undefeated heavyweights. Who's 0 do you think is going to be the first to go? Could be Fury if he doesn't start taking Klitschko more seriously.
Tyson Fury. Wilder will lose as soon as he steps in with a top 10 fighter, but we all know that isn't happening anytime soon.
One thing i can definitely foresee if/when Fury loses is that he'll be the most gracious guy in defeat you'll ever see
Fury only because the dude is fighting live bodies. Joshua is fighting contenders but nobody dangerous and Wilder.....well there is a reason he's called bum squad.
At the moment Fury is the only one guaranteed to be fighting a real dangerous fight so Fury is the most likely. Wilder is fighting Arreola so no major risk there, and we don't know who AJ will face next so can't make any kind of informed decision.