I tried one of these a while back, and found it so hard to narrow it down to five!
EDIT: (and after looking through everybody else's choices, the decission has become much more difficult too..) Hopefully its not too predictable, but I try to get a car for every occasion. It changes all the time, but here are today's five...
Modern Hypercar: Pagani Zonda F Roadster. The noise alone would make me want this, but then I love evrything else about it too!
Classics: Ferrari F40 and 250 GTO, I'm not too sure i need to justify myself here..
A bit of Luxury: Bentley Arnage T, my favourite Bentley, and my favourite luxury car. Just beats the Maserati QP and the updated 2009 Range Rover V8.
Daily Driver: Focus RS, practical, well equipped, and a total weapon too