Family-sedan shoppers no longer have just a few choices; these days it's not just a Camry-versus-Accord world. Look to the latest Sonata, Optima, Fusion, Malibu, Legacy, and 6, and you'll see a full slate of serious contenders, all with slightly different personalities. Two of the newest mid-size sedans, the Nissan Altima and Volkswagen Passat...