Hey, all, I'm just getting into the MR game. Like the other "bank" programs, I'd like to have a fall-back zero-fee MR-earning card in my drawer that will keep me from losing my accumulated MR when/if I close the other MR-earning cards I have. (Always keep one, right?) Anyway, what's the current thinking on the "best" fee-free MR card to keep and why? (I figure that ought to spur some discussion that will be of use to more than just me.) Thanks in advance.