My favorite is actually a really simple family recipe for any occasion, but I have a more gourmet version I like to pull out for gatherings.
Simple Baked M&C:
16oz elbow macaroni (penne, rigatoni, corkscrew all work well too)
8oz block of medium cheddar
8oz block of sharp cheddar
1 teaspoon ground mustard powder
1/4 teaspoon cayenne
1 egg, beaten
Lotta damned butter
Salt and pepper to taste
Milk to cover, description below.
Cook the pasta to aldente in salted water, drain and put in a 9x13 pyrex dish. Cube up the butter sticks, minimum of one whole stick, two sticks is good, and stir it into the pasta. Stir in about 2/3 of the grated cheeses. Season with salt and pepper to taste. Beat the egg, mustard powder, and cayenne in a bowl and distribute into the dish, stirring quickly so the egg doesn't scramble in the hot pasta. Chase the egg with whole milk and pour it in as quickly after adding the egg as possible, again to help keep it from scrambling the egg. Milk should just reach the top of the pasta with bits of the pasta peeking through. Cover the top with remaining cheese and bake uncovered at 375F till the center is bubbling and most of the milk is cooked in.
Smoked Mac n' Cheese:
12oz elbow macaroni
1 cup shredded xtra sharp white cheddar
1 cup shredded gouda
2 cup shredded monterrey jack
1 stick of butter
4 tablespoons flour
2 teaspoons Worcestershire
1 clove finely minced/crushed garlic
1/4C dry white wine
1/2C half & half
1C chicken stock
1 sliced jalapeno
Pecan wood for smoking.
Cook the pasta to aldente in salted water, drain and put in a greased 10" cast iron skillet. Mix all cheeses together and mix in about one cup to the pasta. In a saucepan, melt the butter and add the garlic, only letting the garlic bubble for 30 seconds or so, then add the flour and stir to make a roux for a couple of minutes. Add the worcestershire, wine, chicken stock, and half/half stirring until creamy. (Hint, if you add cold liquid to hot roux, you don't get lumps!) Stir in 2 cups of the cheese until melted in, add salt/pepper to taste, and pour over the pasta. Top with remaining cheese and jalapeno slices. Smoker should be set around 300-325F, using the pecan wood as the smoke source. Put the skillet on a ridged pan to catch spills, and allow to cook for one hour and check it. If it looks like the best M&C you've ever seen, it's done. If not, let it go a little longer till the whole top is browned and bubbling. I've never had any leftovers from this recipe.