Let's Talk Mac and Cheese

What a fantastic, cheap meal. The only insta-meal that even comes close is ramen, but it can't surpass my imitation Italian heritage.

My shit

So lets talk customization. Sort of like a mac and cheese body shop. I've experimented with two new tweaks in the past week. The first one should be mandatory at all times, because it's incredible and simple:

Bacon.

That's it, bacon. Cut a few slices into pieces around half an inch long, start frying it up. Boil that water, and by the time it starts to boil, the bacon should be almost done. Set it on the side until yo' mac and cheese is done, and mix it in after the cheese and milk and stuff is thoroughly stirred in. Be sure to get every piece of bacon in, and add all of the bacon grease too. YOU WILL NOT REGRET IT. The second tweak just came to me when I was looking through the fridge the other day:

Sour cream.

Definitely my favorite condiment, if you can call it that. I love the taste, love the texture, love...everything about it. When I saw it in my fridge, I had the stroke of genius: This is...a dairy product. So is milk. So does sour cream = milk?
I thought so. I replaced the milk with ~equal parts sour cream. What cultivated was a beautifully rich mac and cheese, with a flavor of the gods. Incidentally, when I made mac and cheese today (with bacon again), I switched back to milk. It had the great bacon, which was nice, but it just felt lacking overall.

So Guys, I need your help. What are other incredible mac and cheese tweaks?

Edit: thanks for the suggestions guys, some nice ideas here that I'll have to try out.