I'd go with the BMW as well, or perhaps the Lexus. The BMW for the well engineered and sport oriented design philosophy vs the Lexus for an extremely well designed 'appliance' that simply works and works fantastically. Honestly, I've never been impressed with what I see of the 500+ range Mercedes cars in respect to their price - it seems like you get a lot more with several other brands, and honestly (I'll probably get assaulted for this one ) better reliability elsewhere as well. The Jag's a nice car, especially if we're talking about one of the newer aluminum models (I don't remember when the switch ocurred). However, historical reliability (although they have apparently improved dramatically over the years since Ford got involved) and the short passenger compartment would probably steer me away.

Who am I kidding? I drive an 18 year old Mercedes with 183k, an 11 year old Ford with 157k, and a 23 year old motorcycle. I'll never justify owning any of these (at least not until they're 20 years old).