I'm not especially committed to brands most of the time, but there are a few items I always go back to and stock up on when they're on sale.
These fire roasted canned tomatoes are fantastic. I think a lot of brands are making them now but they give a great smokey flavor to chili or tomato sauce.
Duke's mayonaise is the only one to buy if you're not going to make your own. Any good southerner will tell you so.
I love these canned chipotle peppers in adobe sauce. A lot of recipes call for them now too. I open a can, chop it up in a mini chopper and then put it in the refrigerator. Just a smear on a quesadilla, burrito, taco, pannini, or chili is great!
Nutella pretty much speaks for itself. What's not to love (except the calories). Buy some croissants, open them up and put a smear of nutella on them. Wrap them in foil and warm them in the oven. Voila, you are instantly in France eating a fresh hot chocolate/hazelnut croissant.
And the olives; I love the olives you can get from all of the olive bars (in the grocery stores) now, but for a martini I always have some bottled on hand. I love to mix it up a bit and use olives stuffed with jalapenos or spicy peppers. Adds a nice kick.
I love Barilla pasta and yes they do sell it it Italy, I checked. DeCecco is wonderful but usually expensive, I get it occasionally for entertaining.
There are lots of wonderful icecreams out there and I love to make homemade in the summer but our standard, always have on hand, (usually in two flavors), is Breyers. Vanilla and coffee are my favorites and they're great for topping all kinds of desserts. It's on special a lot so I usually get two for $5.
Have you seen these Dorot herbs in the freezer section? In the winter when I don't have fresh basil on hand it really perks up a dish. It has perforated cubes so you just use what you need. Brilliant.