Place the basil in a blender (don't bother trying this with dried basil; it won't work).
Add the oil, garlic, parsley, salt, pepper, and pine nuts, walnuts, or almonds.
Blend until all are chopped very fine.
Remove from the blender, and add the Parmesan or Romano cheese.
Toss a little of this great sauce with hot thin spaghetti, and top with a little more cheese.