Credit cards may look alike, but when it comes to how pleased people are with their plastic, the differences are dramatic, according to a recent Consumer Reports’ reader survey.

The survey was based on more than 36,000 readers’ experiences with nearly 62,000 credit cards. USAA Federal Savings, the Navy Federal Credit Union and a group of other credit unions scored the highest ratings for customer satisfaction. Those cards received high marks for bill-timing and problem resolution and charged median interest rates between 9 percent and 11 percent, compared with low-scoring credit-card issuers that charged 17 percent.

And while credit-union membership used to be available only to people who were closely connected – for example, having the same employer or geographical location – looser restrictions now make them available to many more people.

Two retailers also scored high. Cabela’s, which sells sporting equipment, and Nordstrom, an upscale department store, each boast a long history of superior customer service.

The nation’s five largest MasterCard and Visa issuers all received undistinguished scores. JPMorgan Chase, Bank of America, Citibank, Capital One and HSBC together control almost 80 percent of the Visa and MasterCard market, and therefore can set take-it-or-leave-it terms. More CR readers who used those banks’ cards complained that they were assessed unfair late fees or experienced unexpected interest-rate increases than did readers who held cards from the top-rated issuers. And none of the five stood out as exceptional at resolving problems.

The two issuers at the bottom of CR’s ratings, Providian (now offered by Washington Mutual) and Direct Merchants, charged the highest median interest rates reported in the survey: 17 percent.

One reason to shop for a good card is that a bad one can be very bad indeed. And they’re getting worse.

Despite congressional hearings chastising issuers for excessive charges and the introduction of several bills designed to clamp down on such practices, credit-card fees continue to climb.

A September 2006 Government Accountability Office study also noted new hidden fees. They included charges for making payments over the phone, which can range from $5 to $15, even when payments are on time.

Many lenders also play tricks when calculating what you owe. Some keep the interest clock ticking from the time they calculate and mail your bill until they receive your payment. If you’ve been carrying a balance and try to pay the bill in full, you’ll find that you still owe interest for that additional period.

Then there’s the old trap called double-cycle billing, which lets you avoid interest charges only if you’ve paid your two previous balances in full. One more practice to look out for is universal default, which allows the issuer to boost your interest rate if you make late payments on other accounts, such as car loans, mortgages or other credit cards, even if you have a spotless repayment history on that particular card.

The bottom line is that, when it comes to credit cards, the deck is stacked against consumers – which is all the more reason to play your cards right.