I always have;

condensed milk
nestle caramel top'n'fill
nestle choc'n'top (same as the top'n'fill only chocolate)
cartons of longlife cream
packets of scotch finger biscuits (the biscuits, cream and top'n'fill/choc'n'top make a dead easy dessert if you get caught out)
cream of mushroom soup (great beef strog base)
dry soup mixes (french onion/spring vegetable/chicken noodle - not much you can't make with those)
tin tomatoes
curry powder
potatoes
pasta
rice
assortment of stocks (beef/chicken/vegetable)
ketcap mannis (sweet soy sauce)
oyster sauce

The freezer is always stocked with beef/lamb/chicken too.