My list looks very much like Mandalinn's except that we are big seafood eaters, so I buy fish for at least 2x a week.
Here's what I almost always have available.
Dried and canned beans (pinto, black, garbanzo, navy, red)
Whole grain pasta (mostly tortellini)
Steel cut oats
Popcorn (best snack ever)
Whole grain bread
Canned tomatoes in all forms - whole, diced, paste, sauce (buy in bulk at Sam's Club)
Lots of spices (I buy them in bulk from Penzey's)
Garlic & onions
Olive oil / peanut oil
Flour (whole grain and white), sugar, baking soda, etc. The usual pantry staples.
Panko bread crumbs
Yogurt (both homemade and Fage brand Greek yogurt)
Sunspire whole fruit strawberry spread (with cane sugar)
Salsa (we go through a large bottle of salsa a week)
Dijon and yellow mustard
Barbecue sauce (DH likes it, I don't. So I'll sometimes put it on his food.)
Kraft Asian Sesame Light Dressing (the only dressing I buy rather than make)
Nature Made peanut butter with flax seed
Sharp cheddar cheese (both in block and shredded form - Costco or Sam's)
Tons of veggies (cabbage, broccoli, celery, zucchini, squash, cabbage, carrots, baby spinach, etc)
Apples (I eat an apple a day or more)
Whatever fruit is on sale (usually pears, grapes, nectarines, sometimes melon)
Boneless, skinless chicken breasts
Whole chickens (when we can get them unprocessed and not Butterball brand)
Pork loin (we buy whole loins from Sam's club and cut them into roasts and chops and freeze them)
Extra lean ground beef (93/7)
Lean ground turkey
Mahi (again, buy frozen filets in bulk at Sam's Club)
Frozen mixed berries (Costco)
Frozen blueberries (Costco)
I think that's about it - I'm sitting upstairs trying to picture the various parts of my kitchen now.
Out of that I can make meals and snacks for us with food left over.
About once a month I'll do a big cooking spree and make a ton of tomato sauce for pizzas and pasta and freeze it. I'll take the chicken carcasses and make chicken broth. I'll make a triple batch of chili and freeze it (before the beans are added). Generally I'll make a bunch of stuff and freeze all of it in smaller portions so that we've got stuff to fall back on if I'm busy or don't feel like cooking much.