An essential simple sauce in the Italian repertoire done properly, is a little masterpiece. Try replacing the parsley with basil, or use some of each.
3 garlic cloves, finely chopped
A large handful of flat-leaf parsley, finely chopped
Cook the spaghetti in plenty of boiling salted water until al dente.
Meanwhile, heat the oil in a heavy-based frying pan over a low heat, and saute the garlic for 1-2 minutes, stirring with a wooden spoon to spread the flavour through the oil.
Add 2 tbsp cooking water to the pan and stir in the parsley. Season with salt and cook for 3 minutes, mixing occasionally.
When the spaghetti is ready, drain it quickly so it is still rather wet and add it to the sauce. Gently toss to coat, then leave for a minute over a low heat before serving on hot plates.