Honestly? For me, it was a home-made macaroni and cheese, made off a recipe I found online. Five kinds of cheese, in a half-milk, half-heavy cream base, with tons of ham... I doubled the amount of pasta and still felt like I was drowning in cheese.
It was amazing, but with every bite my partner and I were rhapsodizing about how it was the most disgusting thing we'd ever eaten. So much butter. So much cheese. So much cream. I'm having heart palpitations just THINKING about it.
ETA: Oh, heard of, not eaten! Hmm. There's a guy on the food channel who just goes around doing huge challenges.