Pat the fish fillets completely dry with paper towels and season lightly with salt and pepper.
In a shallow dish, whisk together the eggs and buttermilk, and in another shallow dish, combine the flour, cornmeal, paprika, garlic powder, onion powder, salt, black pepper, and cayenne pepper.
Heat 2 inches of vegetable oil in a large, heavy skillet or Dutch oven to 350°F.
Dip each fish fillet first in the egg mixture, then in the flour-cornmeal mixture, then back in the egg, and finally back in the flour-cornmeal mixture for a double coating.
Carefully place the coated fish in the hot oil, working in batches to avoid crowding, and fry for 4-5 minutes per side until golden brown and crispy.
Remove the fish to a paper towel-lined plate to drain, and serve immediately with lemon wedges and your favorite sides.