I have a costco business AMX. Earn 4% on travel and gas. 3% food, 2% for dont recall and 1% everything else. Chase Freedom has the best I think. 5% Cash Back in quarterly bonus categories like gas, home improvement and department stores, subject to quarterly enrollment and maximum Unlimited 1% Cash Back on all other purchases with no spending tiers and $150 bonus. I do not carry a balance so the APRs do not matter to me.
http://www.creditcards.com/reward.php