Hey, I didn't notice if anyone mentioned Sabrett brand dogs yet...one of the old school established standards of quality in NYC and North Jersey hot dogs...and they taste damn good, too. I'll add my vote for Nathan's dogs, too...actually tastes like meat and not processed muck.
When I lived downtown Philly on the 600 block of Rodman St...in a nice 1790's-built house I'll add, there used to be a famous hot dog joint right at 6th & Rodman called Levis Hot Dogs. Too bad they closed down a few years ago. But I used to get an unusual setup there called the Levis' Combo which was a very good dog with a fish cake mushed up on top of it...with or without any other additives like mustard and raw onions, and washed down with their best signature drink called Champ Cherry soda.