Annual fee
Only four of the cards we compared had annual fees.

For example, One from American Express applies a $35 charge after the first year. For those with average credit, limited credit or needs-improvement credit, Capital One's No Hassle Cash Rewards has an annual fee of $29. Bank of America's Money Return Platinum Plus Visa credit card carries a $19 fee. The TrueEarnings card from Costco and American Express doesn't have an annual fee with a paid Costco membership.

Tip: Weigh the benefits of the card if it charges an annual fee. "An annual fee might make sense to a big spender if the card has tiers offering higher payouts that more than offset the fee," says Greg McBride, senior financial analyst for Bankrate.com. "Otherwise, avoid annual fees on cash-back cards."

If the card offers other perks that are worth the fee to you, comparison shop to see if you can find a card with the same benefits and no annual fee, urges Curtis Arnold, founder of CardRatings.com and author of "How You Can Profit from Credit Cards." Look for the individual benefits you're interested in on the Web sites of card issuers, as well as sites such as Bankrate.com.

Cash back on 'everyday' categories
While some cash-back cards offer a flat percentage across all types of purchases, nine cards in our survey offer enhanced rebates for spending in "everyday" categories, which typically consist of grocery, drugstore and gasoline purchases. Some apply the enhanced rebates on everyday purchases, such as those at retailers, restaurants and for automobile maintenance. For example, the TrueEarnings card from Costco and American Express offers 3 percent cash back at restaurants, including fast food establishments. Rebates on the cards we surveyed ranged from 1 percent to 5 percent cash back.

These categories can have exceptions, though, so make sure you understand which purchases will earn a higher payout before using the card. For instance, purchases made at warehouse clubs, discount stores and department stores with the Citi Dividend Platinum Select MasterCard won't earn the cash-back rebate of 2 percent. See our survey results for merchant exclusions on the most popular cash-back cards.

Tip: Use our work sheet "What's the best cash-back card for you?" to determine your monthly spending in enhanced rebate categories. Look for the card that offers the highest payout for the categories your most common purchases fall under.