Was proud I planned out buying a couple of pounds of cheddar from the supermarket and keeping it in our spare fridge for a year and had aged cheddar for Thanksgiving baked mac and cheese last November.
If you're ever in Pullman, Washington, stop in at the WSU dairy store and get a few cans of Cougar Gold cheddar. Cheese in a can sounds weird, but it's delicious, made by the students, and it ages really well -- I've got some cans in my fridge which are coming up on a decade old now. It's kind of a waste to use an aged can for mac and cheese, but I used part of a younger can for mac & cheese and it came out beautifully.
Whenever I keep mild or medium cheddar too long it goes "mature" before long, but it doesn't taste good. French cheese, on the other hand, matures (affines) quite nicely at home.