My favorite thing to eat is a big fatty rib eye.
I'm not sure it is a comfort food, per se.
The things that I remember from childhood that make me feel nostalgic when I make them now include:
Pot Roast, especially lots of with quartered onions
Rye toast topped with sliced summer tomatoes, salt &pepper, chocolate milk (good coffee has replaced the chocolate milk)
Crazy Cake with mocha frosting
Soft, yeasty dinner rolls