I think I'd go with the Maseratti Quattroporte, but I am wondering why it depreciates so fast....
Porsche Panamera Turbo.
Sure, the styling is, um, charitably speaking, "interesting", but from the driver's seat the car is gorgeous and the reviewers are universally praising the driving dynamics. I can put up with the hatchback quirkiness for the driving experience a Panamera would deliver.
ZV
Rolls Royce Phantom
and a driver to drive me around in it.
CLS is indeed beautiful, and my favorite Mercedes, but as a BMW guy, I'd probably get one of those super crazy 'high security' edition extended 7 series.
http://www.bmw-security-vehicles.com/security_vehicles/en/7series/7series.html
E63 AMG - not really sure I would consider anything else.
Sure it's not a track car and the Panamera will run all over it, but that thing is really, really...ugly.