My Grocery Shopping List at Costco:
Produce: I usually buy my organic produce at Farmer Market or Trader Joe's because Costco's portion is too big for our family. The food often spoiled before we got chance to finish them. Plus, Farmer Market usually got better quality. However, when they have organic berries and mandarin orange; I usually buy them because we like to have the oranges as snack and we can use berries for many different things.
Meats: organic chicken, beef: short ribs, and bacon
Seafood: salmon, shrimp, and cod (sometimes)
Butter and eggs