The Latin gangs have organized a lot over past twenty years. They also are nowhere as infiltrated as Italian-American Mafia. They don't have as many turncoats either. They have the southwest, California, and now the northeast.

I would put the Asian mob, particularly the Chinese, also near top. Unlike old mafia, the only thing stopping them from growing too big is they assimilate quickly, however authorities don't have the intelligence gathered on them that they do against others.