I have 3 areas built up in North Carolina, where I live. I build as realistic as possible, with Fire, EMS, and Police, including locations of stations and apparatus assignments. My bubbles include:
Wake County - 70 Fire Stations, 5 EMS Stations, and 14 Police Stations so far. I am very close to completing this county in full, only 5 more departments (11 Fire Stations) to add, plus Police and more EMS locations.
Harnett County - 8 Fire Stations, 3 EMS Stations + 1 Hospital, and 3 Police Stations so far. I plan to build the rest of this county at some time as well, but it is one of my least priorities.
Charlotte - 45 Fire Stations (including Charlotte's Fire Admin and Fleet Logistics), 1 EMS Station + 2 Hospitals, and 14 Police Stations. This area is completed. I plan to spread some EMS to a few fire stations, but other than that I may at some point add some county stations in the area too.
Greensboro - 28 Fire Stations, 3 EMS Stations, 2 Police Stations. The city itself is done, but this city is incorporated into a county wide station numbering system, so I want to add all of the county stations as well. I have so far only added 1 for a Tanker.
In all, I have 151 Fire Stations, 12 EMS Stations, and 33 Police Stations, as well as 3 maxed out Hospitals.
And I'm still actively growing, adding more stations here and there as I get funds in my spare time