Tough call. Andre Ward, then Gennedy Golovkin. I always have to tune in for these two. Kovalev and Crawford are close too.
Ggg Chocolatito Gallo Estrada Siri Salido Loma Kov Frankie Gomez Bud Crawford could replace them 2 in the future.
Spence, Kovalev, Ward, Fury, Crawford, Valdez, Loma. Spence, Crawford, Valdez and Loma to be the future of boxing, no doubt.
I forgot to mention Terrence Crawford who is developing into an elite level champion on par with the best such as Ward and Mayweather.