The M5 is just raw power, it is/was the world's fastest 5 door. Would you want to drive this car, with manual transmission, everyday? I would. The 850, as I said at the post below, consumes a lot of gas, its a V12, the Jaguar XK is great but have no personal experience with that particular model. So out of the list I would take the M5. You can seat 5 comfortably, and chase a Porche quite comfortably too. 400 hp!!!!