In a large pot, bring salted water to a boil. Add the spaghetti or linguine and cook according to package instructions until al dente. Drain and set aside.
In a large skillet, heat olive oil over medium heat. Add the chopped onion and sauté until translucent, about 3-4 minutes.
Add minced garlic and red pepper flakes to the skillet. Cook for another minute, stirring frequently to prevent burning.
Pour in crushed tomatoes and add sugar, salt, and pepper. Stir well and let the sauce simmer for about 10 minutes, allowing the flavors to meld.
Add the shrimp to the sauce, cooking for about 5-7 minutes, or until they are opaque and cooked through.
Toss the cooked pasta with the shrimp sauce until well coated. Allow to heat for an additional minute if necessary.
Plate the Shrimp Fra Diavolo, garnishing with fresh basil leaves and a sprinkle of grated Parmesan cheese.