Mine would have to be a Ferrari 250GT Lusso,

http://www.heritageclassics.com/ferrari/63red250gtl/A.jpg

or possibly a Japanese monster to put those Europeans in place, such as the GT-R;

http://www.wallpaper.net.au/wallpaper/automotive/Nissan%20Nismo%20Skyline%20GT-R%20Z%20Tune%201%20-%20800x600.jpg

I'd be in a Zonda. They're comfy, sexy, fast and then theres the noise they make.
http://turbocrime.co.uk/forum/pafiledb/images/screenshots/Zonda%20F.jpg