Can't say I've only one favorite as a be all, end all but in my experience you can do an awfully lot of good with a jar of mayonnaise.
Sandwich spread, salad dressing "watered down" w/ a little vinegar/yougurt and/or sour cream plus your favourite herbs and spices, hey maybe even another condiment like salsa. Apparently can also be used as a marinade for fish or poultry. As a base to make tartar sauce and of course it always makes a great hair and skin conditioner for dry hair and skin.
I doubt the same holds true for Miracle Whip:D;).