I have only had limited experience with Sam's Club, but my family has held an "Executive membership" at the local Costco for quite a while. We use Costco a lot because we are a big family that eats a lot, and buying bulk makes a lot of sense. From my experience, Costco customer service is amazing, and they will return almost anything no questions asked. Friends of ours bought a water trampoline which got a hole in it 2 or so months later. They took it to back to Costco who immediately gave them a new one without any hassle. My family's Exec. membership gives us a better discount on our purchases, but if we do not make enough purchases in a year to make having an Exec. membership worthwhile, they downgrade us at the end of the year (same thing, but less membership fee). I have also found that while Costco often does not have the lowest prices on groceries, they instead have good prices on higher quality products, meaning you get a good price on good stuff as opposed to the cheap stuff in a grocery store. Personally, I love Costco, but for a couple who may not need to buy in bulk often, and who may want to find the cheapest prices, its probably not the place to go.