Well, the Cubs have their billy goat curse, the Red Sox had the Curse of the Bambino, and Philadelphia has the Curse of Every Team Beats Us and Wins a World Championship:
Flyers: 12 times, including the past 3 seasons.
76ers: 11 times, not since 2001, because the 76ers frankly suck.
Eagles: 8 times, including the past season.
Phillies: 8 times, including the past 3 seasons, would have been more, but mostly they've sucked as well.
Bowling: 6 times, including the past 3 seasons.