I've ruled out the Delta AMEX Gold as a choice. Apparently they recently ditched the $99/yr companion credit for airline tickets. With this in mind and after crunching the numbers to estimate my rewards at my rate of spending this card simply is not a good value compared to other offerings.
I'm now leaning towards either the AMEX Blue Cash Preferred or the Capital One Venture Card. I'm a little more partial towards AMEX because I have heard great things about their customer service. I have also heard that it is easier to qualify for their elite cards if you are an existing member. That might be something I want to do in the future.
I want to thank everyone for the advice. This thread has prevented me from being persuaded into a second rate rewards card by good advertising. (I am convinced that credit card companies employ some of the best copywriters in the world).
This post was edited on 10/7 at 4:25 pm