Go to LS460. I got a certified preowned one last month and did search before the the purchase. It is one of the best cars in the market and very safe based on the reviews. One thing you have to keep in mind that it is a Japanes car, on the other hand, Volvo is a "Chinese" car which we should support, shouldn't we?
If you plan to get LS460, I suggest you get one newer than 2010 because of many new updated parts from 2009.