I love strawberries and I prefer to eat them fresh than to use them in a cake or muffin when I can. As summer fades, though, so decreases the availabilty of good fresh strawberries.
Balsamic vinegar makes a great contrast to sweet fruit. This isn't a breaking trend, but that doesn't make it any less true. Though you can certainly do this with perfect, incredibly ripe strawberries, I actually prefer to use slightly less than pristine fruit. The balsamic flavor boosts the sweetness of the berries. Use 1/4 cup balsamic vinegar per cup of sliced berries. Let the mix marinate in the fridge for a few hours, then spoon over yogurt or ice cream.
Use any balsamic, but the best choice - my opinion, of course - is a berry flavored vinegar, like the strawberry balsamic at Trader Joes or a berry balsamic from the St Helena Olive Oil Company.