I have a Chase rewards (mastercard) with no annual fee. 1% cash back (redeemed in $50 chunks). It used to give 3% on gas too until they cut that.
Here's a good one as well:
http://www.chasefreedomnow.com/ , 1% back on everything, 3% back on rotating categories (gas, supermarket, etc.), no annual fee, and $50 for signing up.
I'm like you Michelle, and would rather not get an AMEX card. For people who do, there is a Fidelity card that gives you 2% back on everything in the form of a deposit to a retirement account (so, basically 0% after the next market crash!!). No annual fee on it, but you do have to have a Fidelity account.