Havarti

Havarti cheese is a moist, creamy variety of soft white cow's-milk cheese native to Denmark. It has small, irregular bubbles in it (by comparison, traditional Swiss cheese has very large bubbles). It has a mild, tangy, and rich taste.

And holy crap does it make good grilled cheese sandwiches.

I've used havarti before in my eggs (which is decadently wonderful) and as a cheese for a cold sandwich. But when you melt havarti in between two pieces of buttered bread, you've got yourself a decadent, melty, gooey, delicious treat.

The only grilled cheese sandwich I've ever had that compares was Gruyère on fresh-baked ciabatta at Campanille's grilled cheese night.