Walmart is America's largest grocer, but in Consumer Reports' ratings of 55 supermarkets, Walmart supercenters landed at the bottom, based on a survey of its subscribers. Eight out of ten shoppers had at least one gripe - such as not enough open checkout lanes, or items were out of stock. And Walmart earned low scores for meat and produce quality.

"Many people were drawn to Walmart because of its low prices. But when we surveyed our subscribers, we found that people thought that the prices were as low or even lower at other grocery chains." In fact, seven of the highest-rated supermarkets rated better than Walmart for price.

But no matter where you shop, there are good ways to cut costs. Buy store brands. You'll save about 20 percent on average. And in Consumer Reports taste tests they often score as well as name-brands. Skip cut up fruits and vegetables. These cantaloupes are about a dollar a pound. Cut up they're 4.99 a pound.

Check unit pricing. It's the best way to determine which package size is the most economical. Weekly specials are big bargains. Tod Marks "The idea is that they draw you into the store. But don't be seduced into buying more expensive items that aren't on sale." And beware those "ten for ten dollar" deals. You usually get the same bargain if you just buy one. So only buy what you really need. "

Consumer Reports rated 55 supermarkets for overall satisfaction, as well as prices, service, cleanliness and the quality of the perishables.

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