I prefer fake hotdogs over real ones most of the time. Except these hotdogs that I had in Hong Kong with a thin layer of cheese or butter or something in it. Those were fucking awesome.
Nathans, Ball Park, etc. are all pre-cooked and safe to eat straight out of the package if kept chilled. Cooking them is safer but, you can eat them cold. Just don't let them get up to room temperature, then it would be unsafe to eat.