B vs B by far. Stevenson vs Tank has a less probability of happening as any day Tank can get arrested for busting a cap in a nightclub. Guys with neck tattoos generally end up in prison.
I'm with you on which is likely the best fight. At this point I gotta' go with Bivol because he is a straight boxing virtuoso and the mobility of Beterviev (who should have taken the name Dreadnought or Inevitability or something more awe-inspiring and apocalyptic) is probably waning. This is maybe the fight I would most like to see. But what happens after? It seems like it's kind of a dead end. I kind of hope that if Tank and Stevenson would get up off their fear and realize that the zero is not the pinnacle of boxing, they could shame the other potentially ATG assholes around their size to mix it up and we could have a legit Golden Era. The talent exists right this very minute, but it's slipping away...
"... would get up off their fear and realize that the zero is not the pinnacle of boxing". Man for real. Mayweather era. Man's either a great or a bum. It's just not boxing. All talk. Youtubers are taking over. Onlyfans are taking over. Hopefully fighters fight for the fans sometime soon.