How to Choose the Best Credit Card
According to Smart Money magazine, the way to determine the best deal is to figure out how much a card really costs you. This isn't necessarily in terms of the interest rate since many of us are what the magazine calls revolvers: those who keep balances on their cards and do not pay them off in full.
A calculator offered in the article at the link below is handy in figuring out the cost of a credit card. The goal is to obtain the net interest rate, since many offers come with lower, introductory percentage rates that eventually get increased to much higher rates after a grace period.
A related story on finding the best credit cards  explains in plain English how to find a card based on personal likes and dislikes, factoring in the person who maintains a revolving balance versus the one who pays off balances each month.
If you are interested in other on-line calculators, be sure to check out AccountingWEB's own personal calculators  for free.