Difficult to say, everyone has something to prove. All those before the top 2 have very questionable resumes with inconsistencies. The next 1-2 years will be very telling.
Usyk, Hunter, Joyce, Ruiz, & Whyte. I don't really see how anyone else could be in there, other than maybe Hrgovic.
This is tricky because we'll know more in about a month (after Whyte-Wallin) after most of the top prospects and contenders fight. If Wallin wins next month, (based on his fight with Fury, his pummeling of Breazeale and a win over Whyte) he might be the hottest rising contender in the sport. If Usyk loses Saturday, he might be retired by Monday. If Parker loses his rematch with Chisora, he's pretty much done as far as a top 10 contender goes. We'll know more about everything in days if not weeks. I think Joe Joyce is great. One of my favorites right now. But he turned pro very late. The moment he loses, he's old enough that he may not have a second act. I think if you fought and beat someone like Tony Yoka or Filip Hrgovic, they'll be around long enough in the future that those will always look like strong wins for many years to come. The winner of Ajagba-Sanchez in a couple weeks will definitely be a hot ticket, too. But we're approaching a big shift in the division because the top guys are all in their 30s, so things could change quickly. I'll be a coward and wait a couple more weeks.