Which of the Upstate Cities outside of the NYC area , excluding Buffalo ,had the "best" illegal gambling operations going on in the time of the 1930s ,1940s and ,1950s
So pretty much in all of New York State except NYC and Buffalo.

In terms of being most extensive ,most protected by corrupt police and officials,being run the most professionally and treated by the politicians,police and general population as if it was completely acceptable and almost like being legal. And provided residents jobs in the illegal gambling industry. Also including the other types of businesses that are usually associated with such towns , like after hours drinking,night clubs,strip clubs,prostitution, etc.

My guess would be Saratoga because of Doc Farone and possibly Utica the so called "Sin City". Rochester is bigger but we don't hear much about the gambling there.