1 1/4 cup macaroni
1 1/4 cup grated cheddar cheese
3/4 cup milk
1 tsp salt
2 oz velveta
2 tbl butter
cook macaroni and drain. hold back 1/2 cup grated cheddar, mix eveything else in a baking dish with the hot macaroni. make sure all the cheese is melted and mixed well. top off with the rest of the grated cheese. bake at 400 until cheese melts, about 15 minutes.
I will use my 500th post to address this topic, which is near and dear to my heart.
Box mac-n-cheese has its place, but homemade is really the way to go if you have time. I've made the Alton Brown recipe, and it is very good. I would suggest giving it a go, and then you can modify from there.
I kept the dry mustard, onion, and bay leaf in my standard version, but I leave out the egg.