Credit card issuers continue to sweeten the rewards, hoping to add consumers with excellent credit scores to their portfolios.

The latest appealing offer is from Chase. The Southwest  Airlines Rapid Rewards Premier credit card is now offering 50,000 points after your first purchase, enough for two free roundtrip flights to almost anywhere Southwest flies. There are some drawbacks to the card: a $99 annual fee, a higher APR (14.24%) and cardholders are probably required to have good to excellent credit scores to be granted approval.

Competition among issuers is extremely high as credit card companies try to attract the consumers with the lowest risk: those with high credit scores. According to Mintel Compermedia, credit card offers have more than doubled from 551 million at the end of 2009 to 1.4 billion at the end of 2010. Consumers with good or excellent credit scores are receiving the majority of these solicitations, and rewards seem to be the bait being used to attract new customers. Eight in ten offers are for rewards cards promoting points, miles or cash rebates, up from six in ten offers in 2008.

Some of the other attractive airline miles  credit card offers of 2011 include:

* In April, Chase offered a month-long incentive where new cardholders could earn 100,000 miles with the British Airways Visa Signature Card. New cardmembers received 50,000 bonus British Airways Miles after their first purchase and another 50,000 bonus miles after they spent $2,500 with the card during the first three months.

* In March, Capital One promoted a “Match My Miles Challenge” on their Venture Card. It matched up to 100,000 miles a consumer had in any airline credit card rewards program once the new cardholder spent $1,000 in the first three months on the card.

* Chase currently offers 25,000 bonus miles after the first purchase oneither the Continental Airlines One Pass Plus Card and the United Mileage Plus Card. You also get a $50 statement credit after your first purchase. The One Pass Plus Card also offers 10,000 annual bonus points if you spend $25,000 during the year. However, there is an $85 annual fee for One Pass Plus and a $60 annual fee for United Mileage Plus.

* The Citi Gold/AAdvantage World MasterCard currently gives a new cardholder 30,000 miles on American Airlines after $750 in purchases during the first four months. The $50 annual fee is waived for the first year.

Consumers need to be aware that many of these cards come with a higher interest rate. As with all reward credit cards, the benefits are a good deal only if you pay off your balance in full each month.