I have a Discover card as well as a Chase Bank Visa. Both "give back". Discover "gives" cash, Chase "gives" Amazon.com gift certs. Both have no annual fee. I don't know what the interest rates are, since I pay mine off in full every month.
I put as much stuff as possible on the cards. Discover is my first choice, since ya get cash back. I put my son's daycare on a credit card, since that is a quick way to run up the balance and get more $$$ back. Gas and groceries also go on the card.
Hope that helps!