If crash-test ratings are what count--and they should--it's hard to do any better than the 2013 Kia Optima. With top ratings in every test from the federal government as well as the insurance-funded IIHS, the Optima has an excellent record that's hard to beat.
Those scores from 2011 have since been extended to cover the 2012 and 2013 model years for the Optima, too. That includes 'good' ratings in every test category from the IIHS (except an 'acceptable' small overlap frontal score), making it a Top Safety Pick+ vehicle overall. It also earns five-star scores in all tests--including the side pole test--from the federal government. While the Optima is structurally similar to the Hyundai Sonata, the Kia has a number of different details--which, apparently, make a difference here, as the Sonata only manages a four-star frontal score while the Optima achieves five stars.
Front active headrests are standard in the 2013 Optima, along with front seat-mounted side airbags and side-curtain bags. So is Brake Assist, and Hill Assist Control, which helps avoid rolling back when starting uphill, and electronic stability control.