Best place for mushrooms is in a paper bag. Even if they get forgotten in the back of the fridge they will just dry out, but not go slimy and horrible. And a dried mushroom can be rehydrated in warm water, and is almost as good as fresh. In fact, if I find a good deal on mushrooms I will purposefully buy more than immediately needed, and dry the rest. Won't work for salads, but are wonderfully suited for soups or sauces.