But ketchup is also ok.

When I was younger I would have disagreed, but yes, hot dog and mustard is the amazing and has become my preferred condiment choice. Even better if you can throw some onions on it.

tomatos add a real pop of sweetness, every hot dog i ever eat has mustard and tomato sauce

honestly all of these combos are oretty normal to me except maybe the sweet pie and cheese, but even then i think it could go kinda hard with the correct cheese