Just joined BJ after being a costco member for over 10 years. Like to here which is better.

I joined BJ after a visit today because they had better variety, better store hours and could use my credit card. Not sure if their stuff or prices will be better than Costco.

I actually think that Costco has the better selection, foods, &c., but I'm only a member of BJ's. The reasons are slightly legion[1].

First, I'm just young enough to have never gotten used to carrying around a checkbook or tons of cash. Thus, the ability to use something other than an AmEx or Discover or whichever 2nd tier card Costco allows is nice. Second, BJ's accepts manufacturer's coupons, not just their own. Turns out I am just old enough to still carry around a coupon book-folio-thing when I do grocery shopping. Third, and probably most important to me, BJ's is 5 minutes from my apartment compared to Costco which is 20 minutes away. And, fourth, they have semi-sane hours. They only open at 9 am, but that's better than the 11-12 that Costco does. I just wish they'd open at 5 or something when grocery stores should be open. (I'm still kind of annoyed that the Giant near me opens at 6 am. Guess I got used to the 24-hr King Soopers back in Boulder.)

[1] slightlylegion.com is available!

I would say it totally depends on whether you're asking a lady or a gentleman.
I find it annoying that Costco doesn't take Visa or MC.

If you get a Costco Amex card, you get a rebate on all of your purchases at the end of the year--including purchases that aren't made at Costco.

And rebate time is just about here

I have been a member of both at different times, and of both at the same time. I have done a lot of comparing. In the end, I have chosen to give up BJ's and stick with Costco, but mainly because of the location issue. I noticed two main differences between the chains:

1) Quality: Overall, Costco items are generally higher quality. This applies to food items and non-food items. I remember looking at grilling tools at both. In general, you've got higher quality brands at Costco more often than at BJ's. Also, I have been happier with the Kirkland Signature line than the Berkley & Jensen products. Most importantly, the produce at Costco seems to be a cut above BJ's.

2) Sizes: As a general rule, Costco sells larger quantities than BJs. I remember a particular salad dressing that both stores had. BJ's sold a two-pack of smaller bottles, and Costco had a large bottle that was more than the two small bottles combined. So if you're not feeding a large family, BJ's potentially works better. I have noticed this trend across most product categories.

The one reason why my wife and I switched from Costco to BJ's is the parking lot at the Pentagon City Costco. I have never seen a bigger cluster f**k in my life, entering and exiting is akin to a gladiatorial blood sport.

Have had a Costco membership since 1992. Have had a BJ's membership for a year twice during that time. I do agree that Costco has better quality, nicer stuff, BJ's has more varietie, smaller quantities. And then there is Sams.

Use your Visa check/ATM card at Costco, no problem.

That is probably the worst single parking lot I have ever had the misfortune to experience.