Pass the sauce

What do you have on your chips?  Well, salt and vinegar, but I'm thinking more of sauce.  Tomato sauce for me, but I remember when I was in the forces stationed near the Dutch border, and we used to nip over every now and again, we were introduced to the idea of having mayonnaise on our chips, as the locals did.  It seems once again that there's a bit of a north/south divide in this country, with the north favouring barbecue flavourings and the south hot and spicy, like piri-piri and harissa.  For me, I think a lot depends on what I am having my chips with, but you can't go wrong with tomato ketchup.