I live in LA, and always look forward to my weekly visit to Costco. I haven't tried everything, but wanted some feedback as to what everyone else likes/dislikes:
Parmesan Cheese ($8.39/lb)
Hot Dogs/Pizza/Frozen Yogurt (at food court)
Mozzarella (L.A. doesn't have Joes)
Marinated Pork Loin - really disgusting in flavor and texture
Sausages-All of them have really tough skins.
Coffee - I don't drink, but my wife doesn't like any of the Kirland/Starbucks they sell there.
All I can remember right now.