McDonald's

The world's largest fast food chain by revenue, operating over 40,000 locations across more than 100 countries. McDonald's is not just a restaurant -- it is one of the most studied examples of American cultural export, franchise economics, and supply chain optimization in business history. The Big Mac Index, invented by The Economist in 1986, uses its burger prices as an informal measure of purchasing power parity across currencies. Its architecture, branding, and menu have adapted to local cultures while maintaining a core identity -- a balance that has defined global franchise theory for decades.

Added by @tylerbrooks