With the exception of honey, molasses or maple syrup in small amounts, no refined sugars add any useful nutrients to the diet. The energy provided by sugar is far better coming from unrefined starch. Fruit juices can also provide un-naturally high levels of sugar. It makes much more nutritional sense to eat the fruit, not the processed juice. Artificial sweeteners are also best avoided.
Chocolate is a mixture of fat and sugar and you should restrict this as far as possible.