(I don't use a recipe with this, just add stuff 'til it's right, the way Gram did. So I'm making some estimates here.)
I love all the many different pasta shapes; pretty much anything you like will work ~ macaroni, fusilli, penne like I used today...
Cook your pasta according to the package directions.
In another saucepan, melt about 4 tablespoons of butter and stir in about 4 tablespoons of flour. Make a roux (paste, another thing from Gram). Season with salt and pepper to taste. Stir in about 4 cups of milk ~ we like whole. =) Then start adding your cheese. We use whatever cheese is hanging out in the fridge, so tonight it was some tangy Mexican queso and some shredded cheddar. Mr. Browning likes the sauce thinner, so maybe 2 cups of cheese altogether. Save some to sprinkle on the top when you pour the sauce over the pasta.
I've heard of an infinite number of things to add like bacon, chives, bread crumbs...egg (if you're like our favorite president Reagan.) The possibilities are endless. Toss in whatever sounds good to you at the moment.