I cannot live without carbs, so we always have a lot of Matza, Wasa bread and 4-packs of empty pita buns, because they all keep forever. That, a pre-cut pre-washed lettuce mix and a 0,5kg block of cheese - that's my emergency supply for when I can't be bothered to do much more than add a slice to a slice and use a toaster.

My mother stockpiles frozen veggies, especially those soup mixes (we're big on soups here, but those canned ones taste foul). On lazy days you just pick a frozen pack, add water and perhaps one of those Knorr chicken-broth thingies (or a real chicken breast, if you want the healthier option) and some dice-cut potatoes, boil for 20 minutes (or as long as it takes for the chicken breast to be good), and you've got a hearty meal ready with little effort. I'm lucky in that there are dozens of various frozen veggie mixes available everywhere here.