Depends what I'm using it on.
French's yellow for some things like burgers amd coating pork shoulders before putting them on the smoker.
Hot dogs & polish sausages, any sandwich with salami or turkey - something like Beaver or Boars Head deli mustard with horseradish.
Brats - Boars head spicy mustard w/o the horseradish.
Dijon for making salad dressings and marinades.
Trader Joe's Hot & sour (more like a sweet & sour) mustard for certain cheeses.
and I'm sure I'm forgetting a few...