The bootlegin and sugar business,Gambinos food stamp racket,Frank Costellos slot machines,Giancanas numbers rackets,Jimmy Hoffa,the Vegas skimming,Lucianos and Bonnanos drug business(the french connection and the connection with Sicily),Atlantic city,Havana,famous boxing and other sport matches engineered by the Genovese and the Lucchese fams,the murders on many key informants(Kid Twist for example) and many many many more crimes.These are some of the skims that the mob got away with it(or at least almost) generated billions of cash for years to come for the mob.