Frequent travelers should stick to legacy carriers, because their programs offer more opportunities to earn points through credit cards, such as American Airlines' AAdavantage Citi Mastercard or Delta's Gold Delta SkyMiles American Express.

FORBES: Magazine Article

Color BankAmerica, American Express, Allstate and Travelers in gold.

FORBES: A good year for xenophobes

In fast-growing India, home to a rising middle class, high prices have slowed sales of gold recently, so a consumer base that likes to express itself with shiny accessories has turned to diamonds.

FORBES: Global Bling

American Express's Hilton HHonors Surpass and Premier Rewards Gold cards come with extras such as the ability to earn bonus points on certain categories of spending.

WSJ: Making Sense of the New Premium Card Offers