What food items can't you skimp on?

With the current cost of living, I find myself opting for off-brand products more and more.

Which food items do you feel you can't skimp on because nothing quite hits the spot like that specific brand? Conversely, which off-brand items have you found to be just as good as, or close to, the main brands?

For me, it's tinned tomatoes. Spending 50p on a standard supermarket brand just doesn’t cut it—I’d much rather spend three times that on Mutti.