Cheese is weird. You take milk and you coagulate the fat and protein by injecting it with bacteria that eats lactose and turns it into lactic acid. If you hadn't been eating it all your life, you'd freak out over the concept of it. If I told you, hey, I'm going to take that beverage you're drinking and ferment it, drain the solid chunks out, and turn those into a couple hundred different variants depending on the type of bacteria I use, whether or not I let it get moldy, and how long I let it sit around, you would probably not come over for dinner.
Most "foodies," when they like cheese, like the smelly, oozy cheeses. Not me. I've never even particularly liked blue cheese. No, the cheeses I like are aged cheeses. Parmigiano and Pecorino Romano. Well-aged Gouda and Manchego, which are noticeably different in character from their younger selves, as we all should aspire to be. Beemster's aged Goudas in particular are ridiculously good. And above all else, a really good, sharp, aged Cheddar.
It's probably not coincidence that my favorite cheeses are all prone to forming crystals. Aged cheddars form calcium lactate crystals, like little flakes of salt embedded in the cheese, as a result of the interactions between the lactobacteria and the lactic acid. The parmigiano-type grating cheeses (and that Gouda) can form either calcium lactate crystals or tyrosine crystals from protein breakdown. Either way, if there are enough crystals, you get a little crunch in your cheese. It's great.
There are two cheddars I especially love. The above photo is a ten year old -- yes, ten year old -- cheddar from Carr Valley. This is the IPA of cheddars. It's downright bitter, but in a good way, a beer-sort of bitter. A slightly milder but also more crystal-laden cheese is Grafton Village's four year cheddar, which is also cheaper for me since it's made in NH. For purposes of comparison, the sharp cheddar in your supermarket is usually less than a year old.
I used the Grafton four year in a grilled cheese sandwich, with sourdough bread and beer-braised onions. The onions are like caramelized onions (though I should have caramelized them first and then reduced the beer with them, rather than cooking them in the beer the whole time -- but they're good this way too) which have been cooked all day in beer ... specifically Old Viscosity, a hoppy and very roasted-malty beer that works perfectly with the onions and cheddar.
Now, I know I'm a big fan of sandwiches in general, but this particular sandwich, this combination ... this is one of the greatest sandwiches ever. The funny thing is, I was planning on using rye or pumpernickel, but the store where I buy the Grafton cheese didn't have any, so I went with sourdough (from local bakery the Dutch Epicure).