If you are just talking the US, that is a tough one. For a while there it was salsa. Why? "Because people like to say salsa" Sorry couldn't help it with the Seinfeld reference. I would actually take your ketchup and ranch and rasie you with a both. I work in a public school system and you would be surprised by the number of elementary kids that mix the two together to dip their nuggets in. blech!