Mayonnaise is the greatest condiment EVER
It has so many uses, it is untrue:
On Sandwiches (some sandwiches, i.e. BLT and Club, may NEVER be eaten without it)
Potato Salad
Coleslaw
As a dip for fries
As a base for tartar sauces
For cooling down spicy foods, especially North African foods, i.e. Kofta, Shish, Kebab
Name one other sauce that can do all those things.
Thats right, there isn't one.