I just went through my kitchen. Probably more here than in most of yours, but...
-Jif peanut butter (both extra crunchy and creamy).
-Newman's Own oil&vinegar salad dressing.
-Grey Poupon mustard
-Heinz ketchup
-three different brands of pasta
-Classico pasta sauce, though no particular loyalty.
-Kikkoman's low-sodium soy sauce.
-store brand milk
-Lea&Perrin's Worcestershire sauce
-spices are a mixture of McCormick's, Whole Foods, and the Indian bulk spices out of my parents' pantry.
-Quaker oatmeal
-Morton's table salt
-Beer, wine and cheese: Of course I have preferences, but that's less an issue of brand loyalty.
-Lunch meat for BF: Boar's Head.
-Hershey's cocoa powder (for baking).
-two or three types of canned fish or tomato products.
-breakfast cereals. I have mine; BF bounces around between oatmeal and two or three brands of cold cereal.
Flour and sugar are usually store brands. For Mexican, Chinese, or Thai ingredients, I'm really limited by what I can buy here, since my local grocery store is pretty small. And of course, what I buy here is different from what I'd buy if I'm living at home.