Would you use your miles for upgrades or coach tickets?

Many people who want to get into the frequent flier game often automatically assume that they need to get an airline affinity card, when in fact they'd get a much better bang for their CC$ with hotel awards. Ignoring sign-up bonuses for a second, if you go for coach awards, $50K on a United Mileage Plus Visa card will get you two domestic coach tickets; $50K on a Starwood Amex will get you 5 nights at the Princeville (off-peak) or any other cat 5 property (or 6 nights at a cat 4); on a Hilton Amex it would get you at least six nights at any hotel up to a cat 5, and probably get you a 6-night award at a cat 6 (when you factor in the 5x spending) - you'd also get gold status with that much annual spending. A five-night award at the Princeville blows away two domestic coach tickets.

Get the United Mileage Plus Visa for the bonus miles, but take a look at hotel affinity cards.