"While Walmart's prices are pretty good, we found the deals are at least as good at ten other chains," said Tod Marks of Consumer Reports.
And almost 75 percent of Walmart shoppers polled reported a problem, such as long checkout lines and missing merchandise. Target, another big discounter, rated better than Walmart. But even though it's known for "cheap chic" clothing, Target got some low marks for quality.
"We found that not everybody thinks that 'cheap chic' merchandise is anything to write home about. In fact, women's clothing and jewelry got below average scores," said Marks.
Costco, with its rock-bottom prices, comes out on top in the survey.
While Costco doesn't carry every product, people rated quality on home décor, hardware, jewelry, and watches much better than average, and its clothing did almost as well. Long checkout lines were the one complaint.
"Besides being the top overall scorer, Costco has a great return policy, one of the most generous in the business, with the exception of electronics, you can return anything, anytime, for any reason," said Marks.
Costco has a 90-day return policy for electronics, but unlike other chains, there's no restocking fee.