The most positive aspects of the Columbian Exchange had to do with distributing different kinds of food to places where they had not previously existed. Outside of that, the Exchange was mostly destructive.
The Columbian Exchange allowed for people in Europe to get the benefits of various foods from the New World. These included, among other things, potatoes, corn, and tomatoes. All of these would become very important to various European populations.
Coming the other way were various species of animals. These included cows and pigs. Since the Americas had had no large domesticated sources of meat, these were important sources of protein for New World peoples.