I've had an AMEX Delta Skymiles card for years.
I recently downgraded from a Platinum to a Classic. The annual fee dropped from $135 to something like $65. The interest rates are around 16.9%.
The companion ticket for having a Platinum card is good BUT it does have some restrictions and the paid ticket must meet certain costs to qualify. These are based on which zone in the U.S. you are flying to/from. It will also expire 1 year from issue.
The platinum card has some extra benefits for a frequent traveler but I never used them. The Gold and Classic offer some of the same benefits as the Platinum (double miles on Delta purchases, etc).
I have called them regarding disputes on at least 3 occasions and they were all handled promptly and in my favor.
This link will allow you to compare AMEX cards:
http://www10.americanexpress.com/sif/cd ... 924,00.asp
A questionaire to determine which card is best for you:
http://www66.americanexpress.com/cards/ ... 1&us_nu=dd
Delta Skymiles AMEX special offers:
https://www124.americanexpress.com/card ... enefitList
These links will allow you to compare all cards:
http://www.e-wizdom.com/cc/index.html?g
http://www.moneysupermarket.com/cards/credit_card.asp
All of these links took me less than 10 minutes to find using Google and AMEX.com.