Carrefour gets very busy by Thursday, and the meat is usually poor. The KKOC choice is the other Hypermarche, Auchan on the other side of town, at the end of the N138. Booze and meat are better. Its a useful meeting place too. From there, if you follow the ring road, then just before the Arnage turn off is a Champion. I hear that some like it, but haven't been myself. If you follow the road to Arnage from the Porsche curves and turn left one block before the High Street, you will find the Leclerc. Pretty good but smallish. Alternativly there is the one at Mulsanne (turn left at the roundabout rather than right). Basic, but it has the advantage of a bakers and a chemist next door.
Now for the shopping list! Beer steak beer wine beer bread beer peanuts beer pool beer