When it comes to airline credit cards, there are two ends of the spectrum -- cards issued by the major airlines like Delta and those issued by discount carriers such as Frontier Airlines. The former tend to offer the most perks, while the latter aim to provide more "bang for the buck" to budget-conscious travelers. Let's look at the family of Delta-branded American Express credit cards and the Frontier Airlines MasterCard to see which is the best value, and which might be right for your wallet.

The Delta American Express cards come in three varieties, including the platinum version pictured here.

American Express Delta SkyMiles: Three levels of perks
There are three versions of the Delta-branded American Express cards: Gold, Platinum, and Reserve. All three cards have some perks in common, such as free checked bags for the cardholder and everyone else on the same reservation (up to nine people altogether). All cards also come with priority boarding, 20% savings on in-flight purchases, and earn miles at the rate of two miles per dollar on Delta purchases and one mile per dollar on all other purchases.

The Gold card is the most basic version, and its $95 annual fee ($0 for the first year) is in the ballpark of most other travel rewards cards. In addition to the benefits mentioned above, cardholders can earn 50,000 bonus miles after spending $2,000 in the first three months of membership, and also get a $50 statement credit on their first Delta purchase in that same time frame. Gold (and Platinum) cardholders also receive discounted entry to Delta's Sky Clubs.

The Platinum card's annual fee is $195, and is not waived for the first year. (In the interest of full disclosure, this is the credit card in my wallet as I write this.) However, cardholders get some extra benefits, such as the ability to earn Medallion Qualification Miles, or MQMs, which are the miles that determine frequent flier status, after meeting certain spending thresholds. The sign-up bonus is also pretty generous: at the time of writing, there is an offer of 60,000 bonus miles and 10,000 MQMs after $2,000 in spending in three months, as well as a $100 statement credit after the first Delta purchase (until the end of June). However, the standard offer of 35,000 miles and 5,000 MQMs is still pretty generous.

Perhaps most significantly, the Platinum card comes with a companion certificate, which is like a "buy one get one free" coupon good for a domestic round-trip coach ticket. This perk alone can be worth several times the annual fee.

Finally, the Reserve card comes with a hefty $450 annual fee, but frequent travelers could still get their money's worth. While the sign-up bonus isn't great (10,000 miles and MQMs after the first purchase), the ability to earn MQMs is higher than that of the Platinum card, and the companion ticket is good for both first-class domestic travel and coach. Plus, Reserve cardholders get free Delta Sky Club access; since an annual Sky Club membership usually costs $450, this benefit can be worth the cost of the card for those who travel often.


Frontier Airlines MasterCard: Fewer luxuries, but a good value
There are two versions of the Frontier Airlines MasterCard -- one with no annual fee and one that costs $69 per year.

The card with no annual fee has an introductory bonus of 10,000 miles after the first purchase, and earns at a rate of just one mile for every $2 spent -- one of the lowest rewards rates of any card.

However, the $69 annual fee card could be worth a look. The sign-up bonus of 40,000 miles requires just $500 in spending over three months, and is enough for two round trip tickets anywhere Frontier flies in the U.S. (including Alaska). And, changes can be made to award tickets absolutely free up to eight days before traveling (if you travel often, you know how rare this is).

On an ongoing basis, the card has the same earnings rate as the Delta products -- two miles per dollar on Frontier purchases, and one mile per dollar on everything else. Also, consumers have access to their actual FICO score for free. Another "perk" is that as a MasterCard, the Frontier credit card is more universally accepted than American Express.

There are some downsides to the card. For starters, it doesn't come with free bags or priority boarding privileges. And miles have a rather short expiration date -- you must use your card or make a Frontier purchase every six months or else your miles expire.

Still, this is a good option for budget-minded travelers. When you think about the fact that two people could go to Alaska for free with the sign-up bonus alone (plus taxes), the $69 annual fee looks incredibly cheap.

The takeaway
The airline credit card that is best for you boils down to your personal traveling habits and how much you value the perks. If you tend to travel often and enjoy using airport lounges and priority boarding, and will take advantage of the "free bags" benefit, one of the Delta cards is probably the way to go. On the other hand, for occasional travelers who simply want to get from point A to point B as cheaply as possible, the Frontier Airlines card could be well worth the modest annual fee.

In a nutshell, there is no one-size-fits-all travel credit card. Both of the products discussed here serve their purposes well. It just depends which one makes the most sense for you.