I will warn you now that this dressing isn't for everyone. My partner isn't too fond of it; she finds balsamic vinegar too strongly flavored.
Citrus Balsamic Vinaigrette
1 cup dark balsamic vinegar
zest of 2 oranges
1/3 cup extra virgin olive oil
Soak zest in vinegar for about an hour. Strain.
Whisk in oil slowly until blended.
I served it over fresh greens with pieces of apples, oranges, pears, and nectarines and several blueberries and raspberries. The dressing was wonderfully bright and tangy and set off the sweetness of the fruit nicely while providing a nice little savory tone to the salad.