COMMENTS
Several online publications & I recommend Starwood American Express cards. Points transfer to approximately 40 airlines, almost always 1:1 and for every 20,000 miles you use, you get 5,000 back.
Always go for the cheapest fare, you will acquire free miles over time anyway. The only exception is if your free miles are about to expire and you book a slightly more expensive flight to save your free miles.
Be sure and check the fine print on your credit card when making large charges and do not assume it will result in travel points. We recently found this out with Pentagon Federal Credit Union Visa card when we charged a medical evac flight and did not receive the full points for the charges. As we found out after complaining, they limit their points to a maximum of 10,000 pts per month and 50k per year. We finally found this limitation spelled out in the extremly fine print and on page four of the disclosure! Talk about hiding it! We have now switched our larger charges to American Express, which, as I understand it, has not such restrictions. Plus the points do not expire as they do with the Pentagon Visa card.