So I've only come across them rarely. I don't regard a person saying "would you like to try a hotdog sample?" as bugging. Maybe BJ's is different, but I've never been in one. Nor a Sam's Club. ... Costco has great service and great return policies, as far as we're concerned. More on bogleheads.org

Tell us why your warehouse club membership is best! More on community.clark.com

I've never really noticed much of a difference, tbh. However! I prefer the way Costco treats their employees (Sam's Club is owned by Walmart), and I'm fortunate enough to be able to vote with my dollars, so I use Costco. More on reddit.com

Costco changes its stock depending on local shopping habits and demographics so it's a good idea to tour your local store as a guest of a member before making your decision. Also, depending on local laws you may or may not be able to use the pharmacy without a membership. In general, Costco's gasoline consistently costs less than major chains, its pharmacy negotiates the best out of pocket prices (always ask the pharmacist: your out of pocket price may be less than your deductible), and their auto center is competitive. Costco's food court has held the line on prices and beats most other fast food. Edit: apparently pharmacy access without a membership is chain-wide policy now. Overall Costco focuses on offering quality products fewer price points. Costco isn't the place to find the cheapest sheets and towels, but if you're looking for midrange linens they're often the best deal for the price. Where Costco really shines is customer service. They pay their people a living wage so Costco employees care about doing the job right. For instance it was a Costco Optical employee who figured out one of my eyes has a focal point 3 mm higher than the other, which may seem like a small matter but it affects the prescription because a standard lens won't focus correctly unless it's crooked. No other optical test had ever spotted this. Sooner or later service will matter, and you may not realize when you need it. (I hadn't). My main experience with Sam's Club was picking up a reserve order with a friend who has a membership there. They'd reserved a dozen frozen quiches for an event using the online system, and then called in advance to confirm everything was in order, but on the morning of the event only five quiches were there. None of the store employees had an explanation or gave a damn, and customer service gave the run-around. We ended up having to drive to a different Sam's Club and were nearly late for the event. Also regarding Costco: people tend to love it or hate it depending on how they shop. The people who go on weekends for free samples and make impulse purchases tend to decide the place is a waste; the people who love it shop from a list and check the household inventory before leaving home. And run a search specifically for Costco Business Center. Business Center stores are the restaurant supply arm of Costco. That's the place where you get the best volume discounts, such as mozzarella cheese at $2/lb if you're willing to buy 6 lbs of it. More on reddit.com