IBO Undisputed GBP/Ring IBF WBA Super WBC WBO All the rest of the belts/designations That's the order of importance.
Although to be fair, Zelenoff's "underground" belt has a tremendous "street" rep. Not sure where to rank it though.
So Ruiz & 3G are among the best if IBO is the standard? https://www.iboboxing.com/champions.html IBO or Lineal?
I don't mind the IBO as a belt but I'm glad it's not considered a top 4 belt. It's about a level above the EBU. A suitable intermediary between continental and championship level boxing.
Actually the IBF was the last of the three to be recognized and the in the 90s the WBO was final legitimized.