Legally speaking;
The Bank
The Town Hall
The Police Department / Courtroom
The Fire Department
7-12 Supermarket (The one in the Suburbs, not the one by the Motel; Although they are a chain, so one might argue it'd be the same in both)
The World-Corp lobby, but not the elevators, stairwell, or any property above the lobby
Of course, remember that these are defined as law under "Property That Is Open to the Public for a Limited Purpose", and there are boundaries to these public properties. For instance in the Police Department: You can enter the lobby to apply for a job in the Police Department, or to make a complaint, or to speak with someone there. It is not a public-gathering place, you cannot loiter here, and even though it is "public property" you cannot legally access the majority of the building. This is the same for the bank (behind teller's desk & the vault), the Fire Department (You can enter to apply for job or to report a fire, etc. but not their sleeping quarters), the Town Hall (You can enter the lower area to pay fines, run in an election, etc. but not the mayor's office without permission from USSS), 7-12 Supermarket (Can't go behind the counter, or the back rooms), and so on.
Places such as the hospital, jewelry store, and casino are not legally defined as public buildings because of a myriad of laws and understandings of what "public property" means. Basically, if you have a reason to be there, there is clear area for the public to enter, and a clear distinction of where you should be to do the thing you're there for, that is a public property. Keep in mind that at any point you can be asked to leave by the property owners, or any child-parent (For example, security or police, or in the Town Hall, the Secret Service) to leave, and at such point you are then legally required to leave the property.
Rules-Wise, you'd probably need more clarification from a staff member. Law-wise, this would be the list. I'm just kinda bored and wanted to give the legal definition lol.