Welcome to FlyerTalk It looks like you need to do some research. If you look at any of the airline's web sites, you'll see sections covering how many miles are needed for various regions, be it coach, business, or first. Do you fly with a particular airline now, or are you looking at selecting an airline? You'll likely want a card that will accumulate miles, or allow miles to be transferred, into your airline account.

With the "fee" cards, you get 1 mile for each dollar spent. With the "free" cards, less. There are some good promos out there for some of the airlines, as pointed out above. I got 10,000 miles when I signed up for AA's card last year, but I fly AA. This wouldn't make sense unless you plan to fly them (or the UA promo unless you intend to fly with them).