I would have:
1.Hopkins
2.Jones
3.Calzaghe

I guess you could say its crazy to have B-Hop #1 of the group given he lost to both men, and I guess you could criticize Calzaghe being 3rd on the list cause he beat both men. But when it comes to overall accomplishments over their long careers Hopkins has the edge. Also considering that he arguably never really decisively lost a fight...except maybe to Jones. Prime Jones was an amazing fighter and he is clearly not the same fighter today and hasn't been since winning the heavyweight title. Calzaghe has had a great career and his biggest wins over prime opposition remain his wins against Kessler and Lacy and arguably Hopkins. He did beat RJJ and deserves some credit but it wasnt the career defining win he sought but it keeps his record unblemished and adds a good name to his resume.

I wouldnt argue any order of the greatness of these fighters because all three of them have had unbelievable careers and have made record breaking accomplishments in boxings