I pulled out some items from my pantry to give you an idea of what goods I use the most in every day cooking. Sometimes when I'm low on groceries, I can go in and find stuff that will pull together a quick meal without having to run to the store.

Rice/Bulgur/Quinoa: these things will provide a good base for a meal. I can use rice or quinoa for a casserole or for a side dish with curry. I can use bulgur for a salad or a casserole as well. I also have couscous and brown rice. If you buy these in bulk you will save money.
Red and Green Lentils: used for a bunch of things from soup to stew to salads to lentil patties to lentil loaf.
Split peas: for soup! I also have yellow split peas.
Canned Chipotle Peppers: to add a smoky spicy heat to burritos or enchiladas. I also have canned green chiles.
Agave Syrup: I use this to sweeten tea or if I want to add a slight sweetness to a dish without using sugar. I get this at Trader Joe's for $3!
I also have maple syrup and regular unrefined sugar.

Canned Beans: black, kidney, fava, chickpeas, white...I love them all!
Canned Tomatoes and Tomato Sauce: A must have. I use these the absolute most for sauces and additions to different dishes. I also have tomato paste.
Canned Olives: to add to salads and pasta.
Thai Curry Paste: I like to have small tins different flavors of thai curry paste for curries. You can find these at thai grocery or asian grocery.
Pasta: We have a lot! This can save our lives if we have nothing else. Pasta with some garlic and olive oil is one of the cheapest and most favorite meals around here.
Roasted Red Peppers: for pastas or salad and a component in making vegan "cheez".
Strawberry Jam: For toast, PB & J!

Unsweetened plain soymilk: used a lot in cooking for mashed potatoes, cream sauces, gravies etc. I also have chocolate soymilk, yum.
Coconut milk: for thai curries and desserts.
Indian spice mixes: for indian curries (my favorite!) You can find these at indian grocer or order online.
Nutritional Yeast: for "cheez" sauces as well as a B-12 supplement. KAL is the best tasting brand.
HP Sauce: to put on anything. Ketchup and BBQ sauce are missing from this picture but they would be right next to the HP sauce.