Choosing the best credit card involves more than just choosing the lowest annual percentage rate or APR. If you carry a balance, finding a low-rate card is crucial, but it’s also important to know how the issuer will apply that rate to balances. The most favorable for consumers is the adjusted balance period. Less favorable methods include average daily balance, previous balance and two-cycle balances. For details, see http://www.ftc.gov/bcp/conline/pubs/credit/choose.htm.
See if there is an annual fee as well as late payment, over-limit and cash advance fees. See if the issuer has a grace period, during which no interest charges will accrue. If there is no grace period, the card issuer can start charging interest from the date of purchase, even if you pay off your balance each month.