I generally have all of these lurking in my cupboard or my fridge:
All sorts of mustards, including Grey Poupon or Maille Dijon, Pommery Green Peppercorn Mustard, Zatarain’s Creole Mustard, Batampe Deli Mustard, and almost any non-sweet mustard.
Heinz ketchup.
Hellmann’s Real Mayonnaise and Blue Plate Mayonnaise (from New Orleans)
Real butter, salted and unsalted, both American and European style.
Kikoman soy sauce, Pearl River Mushroom Soy, fish sauce
Honey (clover, sourwood, wildflower, acacia, lavender, orange blossom, and others).
Balsamic Vinegar of Modena – 4 Leaf Private Stock (for fruit), some cheaper balsamic vinegar for salads, red wine vinegar, cider vinegar, and rice wine vinegar.
Bertolli olive oil, Colavita Extra Virgin Olive Oil, truffle-infused olive oil, walnut oil, and Asian sesame oil.
Sriracha Hot Sauce, Tabasco, Yucatan Sunshine Hot Sauce, Bufalo Brand Chipotle Hot Sauce.
Worcestshire sauce, Maggi, Robert Rothschild Tandoori Sauce (wonderful blended with yogurt and used both as a marinade and as a dipping sauce).
Maple syrup (the real stuff), Brown sugar, White sugar, Confectioner’s sugar, Nutella (because I can’t buy Nucita in the US), and Adams’ Port Wine Reduction (a major time-saver).
Anchovies packed in oil, capers, sun dried tomatoes, ground Horseradish, and shiitake mushrooms.
An enormous array of canned and bottled salsas of various sorts.
Plain yogurt, preferably Greek-style.
My current rave is Adams’ Chipotle Powder, which is wonderful on meat-based sandwiches.
Damn! Now I’m hungry!