Coming from the airport, going to Orient, my best suggestions would be in either order, either
Carrefour--Used to be Cole Bay Grand Marche, now called Carrefour. Your taxi driver will know exactly where it is, but for your information, it's over the causeway, make a right, and it's very close on the right hand side. Coming out, make a left and head toward the french side through Marigot. Good selection and prices, great selection of french products

OR

Super U--In Marigot, where Match used to be, years ago. Great prices and selection. On the French side, but they accept Dollars at one to one. Great selection of wines at cheap prices. Beautiful produce and meats, and a bakery right beside the store.

Do NOT go to Simply in Hope Estate. There have been several recent reports of bare shelves, dirty store, etc., there.

Another option, for a much smaller store, but with a decent selection of items, is Petit Casino, in Orient Village. It's a very well stocked store. Prices higher than Super U or Carrefour, but you can walk there and I think that they will take you back 'home' within the immediate Orient area, with your groceries.