I voted mayo just to watch the world burn, it truly is gross.
My fry memories were formed at Central PA racetracks and late night diners, so there are two correct ways to get it done. First, huge dose of vinegar, gotta be first so more salt sticks to them. Hey look, it's snowing!!!. Lastly, lots of ketchup.
Or the diner method, covered in brown gravy. Pass the salt.