How about neither?  We’ve gone to just carrying our groceries, by hand, individually out to the car.  It takes a long time, but it’s good exercise.  Actually, we bought a few of those green, reusable cloth-type bags for our grocery shopping.  They cost about a buck, and every time you bring them back to the store, either Hy-Vee or Price Chopper, they give you 5 cents back.  Price Chopper usually doesn’t even care how many bags you actually need or fill, they just count the whole stack you brought in and give you a nice little chunk o’ money off you bill.  Hey, after 20 visits, you’re making pure profit off those bad boys, huh?

But if you have to choose between paper or plastic, choose plastic.  Plastic bags use 70% less energy to produce than paper bags, they generate 80% less waster, and they take 91% less energy to recycle per pound.