Chinese food, specifically any of the chicken ones. General Tso's is probably my preferred. When it's cold, you get more of the sweetness out of the sauce rather than the spiciness trying to overpower it.
Also lasagna. That shits delicious hot or cold.
I always love eating cake cold, like, I don't mean just "non-warmed", I mean, an entire day in the fridge cold.
Uhh, let's see...Reese's cups? I originally did it to delay them melting in my fingers, but I ended up discovering a personal treat.
This is a bit specific to frozen meals, but only one part of them. you know those frozen meals that have those small brownies in them? It's usually in a type of batter form? Yeah, I refuse to eat them cooked. I always eat them frozen like that. It's kind of like fudge flavored icecream at that point. It seems to taste a hell of a lot better than the crappy form it is in when cooked in the microwave.