Most things as sweet and tasty as cantaloupe are nowhere near as good for you. Check out that calorie count: only 25 calories per cup! And unlike some vegetables which tempt you to add butter or cheese or some fruit which just begs for whipped cream, you'll likely be eating your cantaloupe as-is. Winner!
In addition to being low calorie, cantaloupe also provides a good amount of vitamins A and C and isn't too high in carbs. Compare this to watermelon which provides significantly lower levels of vitamins with about twice the carbohydrates and (this surprised me) more calories.