Most things I can cook from memory are the basics like macaroni cheese, which I have cooked so many times in the past that the method has become embedded in the back of my mind. I am getting pretty good at making chicken noodle soup from memory... though last time I did that I made a pretty big broth error. :-[

What I really like to is bake stuff like cakes (and the like). Though I am pretty confident of my cake baking skills, the only cake I will make without a recipe at hand is a sponge cake. More difficult foods intimidate me enough to have me go by recipe, especially with meringue, which I have had some pretty depressing results with even when I have a recipe.