I have no idea who has the best deal. Use it as much as you can and pay it down every month. That way you never have to pay interest anyway. I don't even know what interest rate my card is, I never pay it.
I've been doing that for years. I probably run about $2 - $3 through it each month. Since its all paid before the grace period ends, I never pay interest. But it has done wonders for my credit rating. When I went to buy a home 2 years ago, I found out I had an 811. I asked the loan agent how it could be so high, he said it was probably the credit card.
If you are married - make sure your wife is a joint account holder, not just a named user of the card. We found out the hard way that the latter does nothing to help your wife. My wife's credit was in the mid 700's - despite otherwise similar credit history - just because we didn't make it a joint account.
I actually don't pay it down every month per se - instead every time a paycheck comes in I pay half the outstanding balance. This usually happens three times a month. But if the balance goes over $2000 I pay it down to 1k no matter when the next pay check is.
This post was edited on 9/10 at 4:47 pm