Pointers for making mac and cheese
If you want a very saucy dish, use a pasta shape that has some curl (elbows, little ears, bow ties, corkscrews) or hollow centers (penne, rigatoni, shells).
Pasta should not cook through initially if it bakes more later. Any extra liquid in the dish will be absorbed by the pasta.
For a crusty top, leave bread on the counter to turn hard. Then work it in a food processor. Or use the Japanese crumbs called panko, which add extra crunch.
Cheeses should melt easily. Swiss Emmental, mozzarella, fontina, feta, and cheddar are all good choices.
All kinds of salty, smoky accents make fine garnishes on a plain mac. Add crumbled bacon, lobster meat, sauteed mushrooms, shaves of truffle, or dots of caviar.