We have our set things that we buy only at bj's & have learned what are good deals vs bad deals there....the hard way.
Beef - I don't know where they get their beef from, but it is far better then any beef I can find at any of our local stores. We even buy the 3.99 lb steaks (which is very cheap) and every time we cook them on the grill they far surpass any steak at any restaurant, they melt in your mouth.
Milk
Eggs
Lipton tea bags
totino's pizza rolls
coffee
microwave popcorn when they send out the $5 off coupon
some seasonings (montreal steak seasoning, highly recommend)
country crock butter
Went to BJ's today just for steak tips. The quality of the beef is just short of a butcher shop we frequent for special occasions. Also love the prepacked Perdue chicken breasts/thighs etc. Their Deli sells Dietz and Watson brand cold cuts. The Honey turkery at my local grocer store goes for $9.99/lb. BJ's has it for $5.99. There are Purdue already cooked Roasters' for $4.99 I think they are 3 pounds compared to my grocer store for a 1 1/2 for 3.99.
I love the Berkley and Jensen bread - 2 loaves for $3.50 (individually wrapped so you can toss one in the freezer.
The Berkley and Jensen Columbian coffee is the only coffee we will buy.
DH likes those Perdue precooked chicken strips - They are (i think) $9.99 for a 3 pack.
I also love the containers of Jack Daniels pulled pork.
I am going to have to try that coffee - that is another thing we always buy there - but normally the Folgers.
I buy - Charmin toilet paper, Bounty Paper towels, Puff's tissues but only with the BJ's coupons plus a manufactures coupon. Same with Tide, Dawn, Windex.
Mitchum deodorant, tooth paste, BJ's brand vitamins, BJ brand shampoo's (Matrix knockoff), BJ brand advil, advil pm.
Some of the clothes are a good deal. DVD's used to be a deal - but sometimes you can find cheaper at Target.
I have a very old Palm pilot - with a free program called handy shopper. I have entered prices over the years of my local grocery store and there is a comparison page in the program. It's cool because it takes into cosideration the quantity of the product (48 oz bottle compared to the 120 oz bottle) and will tell the better value. Because of it I don't buy milk, eggs, cream, butter there. My local grocery store is cheaper.
Pay attention to their coupons - we have bought tires there also. Propane is a lot cheaper for the grill.
Janis