The word "complement" means "to complete or bring to perfection," and that is precisely how I feel about melty ice cream regarding gooey-warm fruit desserts. You can't go wrong with vanilla, but ginger is another flavor that pairs with every fruit I can think of - apples, pears and quince; berries, figs, melons, peaches, apricots and plums; tropical fruits; all citrus; and even chocolate (which is made from the seed of a fruit).