I submit my pick for the ultimate daily driver:
2010 Mercedes Benz S65 AMG
5.5L SOHC Twin Turbo V12
604hp
738ft/lb
11.975@118mph 1/4mile
Smooth, comfortable, roomy, and ridiculously fast. I also like it better than the Maybach. I think it looks better and is a little more stealth. If I were going more exotic (or 2 door) I would pick one of these three:
Bentley Continental GT
Rolls Royce 200EX
Aston Martin Rapide
I think the maintenance and reliability would be way more on any of those though than the Mercedes.