Really great chocolate is my favorite ANYTHING. But for real food, a fantastic grilled steak (no weird spices, just salt and pepper, with grilled onions.
The truth is, ANY good food that someone else graciously prepares for me, makes me happy. What I like depends on my mood. Sometimes, all one needs is a really cold glass of water, or really great hot cup of brewed coffee.
Best thing of all, though is fresh challah baking.