can't vouch for capital one, but i think that all of them are pretty much the same. No matter what commercials claim, there will always be blackout dates... airlines didn't get where they are by handing out free flights ya know?
...I would recommend finding a credit card for an international/domestic carrier that is prominent from the airport you fly from most frequently.
If you are planning on traveling abroad with that credit card, you might want to keep some of the following information about fees in mind (might save you more than you would with that cheaper ticket).
What it is When you pay with a credit card overseas or take money out of an ATM, your bank tacks on a foreign-transaction fee.
What's so bad The fee has skyrocketed. A few years ago, you often paid only the 1% that Visa and MasterCard impose.
Ouch! Chase collects $3 for each ATM withdrawal plus 3%. Bank of America, Chase, Citibank and Wells Fargo charge 3% on debit and credit.
What you can do You typically get the best conversion rate using a credit card or an ATM, even after the fee. For purchases, stick with low-fee cards. Capital One has no fees. Washington Mutual and Wachovia charge only 1%, American Express 2%. See if you can use an ATM that's associated with your bank. As of December, Citibank customers don't pay a dime at the bank's overseas ATMs. Bank of America allows free ATM withdrawals at affiliated banks.
Do not go with Capital One. I don't remember why, so I hope you don't take this post with a grain of salt. I remeber looking through all of this 2 years ago and I can't remember why capital one sucked so much. I would go with an airline specific one or similar. Not Capital one. Hope this steers you in the right research direction.