I think by now everyone knows the drill. Massive amounts of stuff for a better price than if you were to buy in smaller quantities elsewhere. Of all of the warehouse clubs I would have to say that Costco is our preference. It just seems cleaner and better lit than the others.
One trend that is starting to bum us out is the way that Costco is replacing more and more of the brand names with their own "Kirkland" brand.
We avoid the produce. While the deals are plentiful, the fruit and veggies seem to be past their prime before they even leave the store.
We would like to see better options in the meat department (organic, grass fed / finished meats, local suppliers, etc).