Rex Tso in Hong Kong not a world champion but he stopped his professional career for return in amateur, he was ranked 2 or 3 I don't remember by the WBO for to be a world challenger against Naoya Inoue... He is always very popular in Hong Kong actually. Chocolatito in Nicaragua & Srisaket Sor Rungvisai in Thailand actually. In the past in Japan Katsuya Onizuka was the most popular boxer by each class of population during the 90's.
Depending on the era, Julio Cesar Chavez, Ruben Olivares and Kid Azteca were the idols of Mexico Japan - Fighting Harada Italy - Primo Carnera & Nino Benvenuti Scotland - Ken Buchanan & Benny Lynch
Though not a favourite of mine Ricky Hatton has to get a mention.His man of the people persona made him extremely popular