The worst thing I've found is false labeling. I have been a long-time customer of Boboli pre-baked pizza crusts (yes I know I should bake the crust myself), usually buying the 2-item package of 8-inch mini-crusts. In the last year or so, I suddenly noticed that the normal amount of mozarella that I grate onto the pizza had become significantly more than enough to cover the surface. Sure enough, the item labeled as 8-inch diameter is now actually 7.5 inches in diameter, I have confirmed this over multiple recent purchases.

That is over 12% shrinkage.

What always annoys me are zero* calorie drinks. Zero calories? Well, close enough to zero per-serving that they just rounded down a few. Also, there are about 5 "servings" in the bottle.

Coca Cola, Sprite etc changed their can size from 330ml to 200ml overnight here in Indonesia, without changing the price. Guess it’s better than a ~30% price increase.