I like having a rewards card of some sort. My policy is to use it for all of my monthly purchases, then pay it in full every month. This was earning me 1k to 2k miles per month. Thus the interest rate isn't very important, but a none-to-small fee would be nice. What are the best rewards out there? I like earning miles, because I fly a lot -- but maybe there is something more valuable.
So of course I'll ask the internet.... What do you use?