As a Philadelphia-area native who long ago left home to come to New York, I am always cheered by something good happening in Philadelphia. Not patronizing-good, like being deemed the Sixth Borough, but actually good — something that highlights the city’s attributes without mentioning its sports teams. Great news: Philadelphians are the most generous tippers in the country. According to Zagat’s Philadelphia Restaurant Guide, out today, Philly eaters tip 19.6 percent, on average. That’s better than New York City and the rest of the entire country, which averages 19 percent. But why such generosity? Maybe because Philadelphia has lots of BYO restaurants; alcohol often isn’t factored into the check. So despite an obstructive city wage tax, a disproportionate crime rate, and that chronic second-best feeling, Philadelphians can hold their heads high. They’re not cheap.