The Southwest Premier Business credit card is an especially good option for those of you interested in earning the Southwest Companion Pass since the points earned on the card count toward the pass. (rewardexpert.com)
Finally, if you want the ability to earn tons of points but don't want to be locked into the United award chart (just in case there's a better option for some of your travel), you can look to Chase cards that earn Ultimate Rewards. (upgradedpoints.com)
This might be a good option for all of us. (detoxinista.com)