Shh, come in close. I'll let you in on my secret. I get a box labeled "Kraft" and I get some butter and milk like the box says and I mix it all together and it comes out gre... On second thought, I burnt the last Mac & Cheese I made. Just ignore me!
It's all in the cheese. I use 4 - 5 different kinds of cheese. Cheddar, Parmesan, Mozzarella, are the basic ones. I like switching it up and adding Gruyere, Blue, Monterey Jack, &/or Queso. I also add a dash of chipotle seasoning.