I've been on a tear lately for Chicago Style Hot Dogs - The ones said to be 'dragged through a garden'. Hot Dog. Bun. Mustard. Relish. Onions. Tomatoes. Peppers. Celery Salt.
Most of the hot dogs sold in the supermarkets are not very authentic. The local high-end specialty grover sells 'Chicago style dogs' but they are terrible.
I am happy to say however that I've recently discovered the Nathan's Famous brand. There flavor is excellent. And the best news is that the co-op grover 2 miles from my house carries them.
If you want to make an authentic Chicago Style Hot Dog then I recommend Nathan's Famous Natural Casing Beef Franks.