Preheat the oven to 375º.
Line two 13x9x2 inch pans with baking liners or grease or spray them. Add 1 or 2 tablespoons of water to the bottom of the pan.
In a small fry pan, sauté the 3 tablespoons of butter, celery, and garlic until soft but not browned. Then pour it into a large mixing bowl. Set aside.
Crush the Ritz crackers by hand or with a food processor and add them to the bowl, along with the grated cheese.
Stir in the melted butter, lemon juice, parsley, white wine, and black pepper. The mixture will be dry and will just hold together. Set aside.
Remove the shells from the shrimp but leave the tails on. Turn the shrimp with the inside face up and butterfly the shrimp (run a sharp knife down the length of the inside, but not all the way through). Remove the black vein.
Flatten the shrimp at the cut and place them in the prepared pans cut-side up and the tails turned up.
Mound about 1 tablespoon of the filling inside the cut of each shrimp.
Lightly sprinkle the stuffed shrimp with paprika if you wish.
Bake at 375º for 15-20 minutes or until the shrimp is cooked and the stuffing is lightly browned on top.
Serve with lemon wedges and extra sprigs of fresh parsley to the dish.