Best are no fee proprietary grocery store cards where you were going to shop anyway. Maximum return, no fees or distortion in your shopping pattern and 2x the MRs. And the Cardinals of The (AMEX) Spanish Inquisition won't try to burn you at the stake for effectively buying (semi) cash equivalents with their credit cards.
Originally Posted by
thetravelabstract
As for GC's? I have heard AmEx is a good general card. Or buy GC's from where you normally buy your groceries.