Our pals-in-arms at the Consumer Reports National Research Center recently asked more than 26,000 readers to rate their shopping experiences at the nation’s top retailers — both in-store and online — and in spite of being a members’ only warehouse store, Costco came out looking the best.

Survey respondents told CR about their 55,108 shopping experiences at Costco, JCPenney, Kmart, Kohl’s, Macy’s, Meijer, Sam’s Club, Sears, Target, and Walmart and on those retailers’ websites.

When all the results were tallied, Costco was the only chain to earn an outstanding grade for the overall quality of its merchandise, both at its bricks-and-mortar stores and online.

Costco also earned above-average scores in all 10 product categories, including electronic entertainment, jewelry, and sporting goods.

Costco’s website was lauded by respondents for its layout, product value and its checkout process.

The only real downsides to the retailer’s results came from below average scores for its in-store selection, the long checkout lines. Its stores were also called out for a lack of fitting rooms.

Some other notes from the survey, which is available in the March issue of Consumer Reports and on ConsumerReports.org:

* Not surprisingly, CR readers gave low marks to Target’s revamped website for being not especially easy to use.

* Macy’s was the only chain besides Costco to receive raves for its kitchenware and personal-care products.

* While Sears’ stores and website had similar overall scores, the chain’s online customer service rated lower than its walk-in service.

* Walmart and Kmart stores scored much lower than those of other retailers. Walmart might be associated with low prices, but respondents said the product value was better at Costco and Kohl’s. Kmart was the only chain to score below average for value. Kmart also received low marks for selection, service, and checkout speed.

* 23% of the Walmart shoppers who returned an item to one of its stores the previous year reported at least one problem, significantly more than at any other retailer.

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