Aside from the whole “I really try to buy locally & seasonally” (which I do!), there are a few produce items which I consider staples, simply because having them around means that I have a lot of options for food-making. And when it comes to food-making, I am a fan of options.
BLUE JEAN GOURMET PRODUCE FAVORITES: 
Avocados
Cilantro (stored like this, I can make it last for a month in the fridge!)
Garlic
Ginger (which you can freeze, after peeling & chopping)
Lemons
Limes
Mushrooms
Onions
Pears (great for snacking & salads)
Potatoes (I’m a fan of the little red ones; store them far away from onions, they’ll last longer)
Parsley (flat-leaf Italian; store in a large Ziploc bag with a folded paper towel)
Spinach or mixed greens
Late Summer/Early Autumn Favorites:
Zucchini (quick-saute with black beans for easy quesadillas or burritos)
Tomatoes (BLTs for an easy dinner, make-your-own tomato sauce to freeze for winter)
Bosc pears (so delicious with almond butter as a breakfast sandwich!)
Butternut squash (easily roasted in the oven, either sweet or savory)
Broccolini (saute with garlic, garnish with pine nuts & shaved Parmesan)
Blue Jean Gourmet 