Almost all paper goods, specifically Kirkland brand.
Canned veggies are all the same as well, so whatever’s cheapest
most dried herbs and spices
staples like flour, butter, sugar, oil, etc. they are basic and as long as you are getting the kind you need (like AP flour or dark brown sugar) there isn’t any room for differences that the average consumer could notice anyways
If you make bread you can tell a difference between brands of flour, and the more expensive stuff is usually noticably better.