But Discover gives you cash back! I get hundreds of dollars a year back from them. (I use my Discover card whenever possible: groceries, gas, monthly ISP fees, etc.)

I refuse to use a debit card. Debit cards don't have the protections that ATM cards and credit cards have. And if there's a mistake or someone swipes it, my checks could start bouncing. A credit card is just so much easier.

I do have an Amex card that gives me vouchers for groceries at Shop-Rite. But Shop-Rite pulled out of this area, and Amex isn't widely accepted, so I rarely use it.