If you're thinking about the organization's structure:
* Law enforcement: This emphasizes the contrast of lawful authorities versus criminal organizations.
* Legitimate business: This highlights the difference between legal and illegal operations.
If you're thinking about the mafia's methods:
* Honesty: This contrasts the mafia's use of violence, intimidation, and corruption with ethical behavior.
* Peace: This contrasts the mafia's violence and conflict with a state of tranquility.
If you're thinking about the mafia's overall impact:
* Justice: This emphasizes the contrast between the mafia's disregard for the law and the pursuit of fairness.
* Community: This highlights the contrast between the mafia's self-serving interests and the well-being of the public.
Ultimately, the best "opposite" of "mafia" depends on the specific context and the aspect you want to emphasize.