Your perfect lake might be a pool only you and the loons know about. Or a serpentine reservoir ruffled by the wake of speedboats. Or one of the mighty Great Lakes, with beaches as fine as any ocean's. Whether you're searching for serenity or want to make a splash, we have the place for your perfect lakeside vacation. These 25 spots are each cool for a different reason, but they've got one thing in common: a liquid heart.