Bottled water and gasoline are rather popular as well.
Pizza and alcohol are important, but what really gets me is when people risk their lives going out in a storm to buy milk. Any household should have enough food in the freezer/pantry/cupboard to keep a family alive for a few days. Big deal if you don't have milk, drink water instead. Thaw out the chicken that you have buried in the bottom of the freezer.
Our biggest need would be gasoline to run the generator. We can run the water pump, sump pump, fridge, freezers, microwave, etc. We keep enough gas on hand to run it non-stop for at least 24 hours. And if we ever got to the point that we couldn't keep warm enough in the house, several of our neighbours have wood stoves.