The trick is to add a beaten egg or two to your cheese sauce. This makes it go thick and "custardy" (in a quiche-y way), rather than remaining a thick sauce. I discovered this after years of looking for the perfect Moussaka recipe.
I prefer Jarlsberg (and/or Emmenthal swiss) cheese, grated into cheese sauces - they taste deeper than cheddar. If you need some extra bite, add grated Parmesan to taste.
Try following step 4 (béchamel sauce) in this recipe for Moussaka, then stir in some cooked Macaroni before baking in the oven. It is the baking that makes the egg react and the whole mixture "rises" to give that wonderful thick texture.

You people and your cheesy pasta are killing me. I shouldn't be hungry but I am, and reading this?

a consistency like curly pasta with melted Cheez-Wiz

I died. No, I plotzed. One of those. Really.

A bit of flour dissolved in cold water, and then beaten into the soupy stuff, is a less classy way to get a thick sauce.

Not sure if this is what you have in mind, but I love the way this mac 'n' cheese turned out.

I think what I'm looking for is something that's closer to melted Velveeta than to an alfredo sauce -- I don't want it to be mainly white and parmigiany, I want mainly cheddar and super-gooey.

Have you checked out this blog?

Oooh oooh oooh oooh oooh. Amro, I had not seen that, and I think their link to Martha Stewart's version might be exactly what I was looking for.

Cool! Let us know how it turns out.

ooOoOooooOoOoO Silvertone's mac and cheese.

I make the Martha Stewart version regularly. It isn't a lot like the Silvertone's version, but I vary the cheeses every time I make it so it's possible that I haven't hit the right combination yet.

I emailed Silvertone's to ask if they'd share. No harm in asking, right?

Their reply: "Sorry [initapplette], we keep that recipe to ourselves."

And with good reason! It keeps people coming in the door! :-)

Sigh. Silvertone's mac and cheese and Chacarero's sandwiches might be the only two reasons I'd consider moving back to Boston. :-)

I like to add plain whole-milk yogurt. (Mmm....)