The rule seems to be that the more you cook, the less nutrients will remain in the food, but I know there are exceptions, and I wanted to find out what they are. Here are a couple I found. Have you got any others?
cooking carrots actually enhances the digestibility of the beta carotene
heat processing actually enhanced the nutritional value of tomatoes by increasing the lycopene content that can be absorbed by the body, as well as the total antioxidant activity.