People from Caguas (cagüeños) and Ponce (ponceños) are the traditional contenders.
Ponceños simply believe they are la última Coca-Cola del desierto—literally “the last Coca-Cola in the desert,” or the greatest and most desirable thing around. Ponce es Ponce y el resto es parking (“Ponce is Ponce and the rest is parking”) is a common slogan.
Cagüeños, meanwhile, are widely treated as a red flag. They are supposedly toxic and believe Caguas is far more impressive than it really is.