Cook the spaghetti in boiling water extremely al dente and then bake it with cheese. Don't add oil to the water - it will hamper the sauce's ability to cling to the pasta. The spaghetti will cook further in the oven and absorb the flavors from the sauce and cheese. Try making a sauce from scratch rather than using a sauce from a jar. Add fresh or dried herbs to give it an authentic Italian flavor. Experiment with cheese blends to find the one you like best. A good quality cheese can really "kick spaghetti up" a notch! Don't confine yourself to the traditional "red sauce." Chicken and parmesan, olives and feta, even BBQ sauce with chopped meat can all yield surprisingly delicious results!