I use Barclays's Sallie Mae card to get 5% back on groceries all year, but I'll be using my Chase Freedom for groceries this month to keep the account open, because I haven't used it since qualifying for the sign-on bonus in March. Because Chase has some of the most lucrative bonuses for travel-oriented cards, I'd like to refrain from pissing them off.
For those with large families, the $1500 quarterly limit on rewards for groceries will be more useful than the $250 monthly cap imposed by Barclays, but my spending at grocery stores seldom rises above $100 per month. The Freedom category also includes movie theaters and Starbucks. I'll be surprised if I wind up spending anything at either. For me, the categories (restaurants for Q2, gas for Q3, and Amazon for Q4) seem more practical than Discover's, but both will be spending quality time in the sock drawer once January is over.
The Sallie Mae card was originally marketed to students, so it emphasizes typical studently expenses, and in addition to the deal on groceries, gives 5% cash back on up to $250 worth of gas and $750 spent at bookstores (including Amazon) each month. People give me Amazon gift cards for any and all occasions, so I have an absurd balance to spend, and have never used my Sallie Mae card there. No, I have no affiliation with Barclays, but I just flove this card!