In a large bowl, whisk together flour, baking powder, salt, Old Bay, and sugar. Add the eggs, milk, butter and hot sauce and stir until just combined. Remove the corn kernels from the cob and add to the batter along with the potatoes, shrimp, and smoked sausage. Fold until combined and allow to rest.
Fill a pot with about 3 inches of oil and heat to 365°F. Once hot, using a small ice cream or cookie scooper, carefully drop round spoonfuls of the batter into the hot oil, a few at a time. Fry, turning every now and then until golden brown and fully cooked through, about 5 to 8 minutes. Transfer to paper towels or a wire rack and continue frying the rest.
To make the sauce, stir together the mayo, parsley, garlic, lemon zest and juice, Old Bay seasoning and hot sauce.
Serve the fritters warm with the sauce for dipping. Garnish with parsley and serve with lemon wedges. Enjoy!