I'd like to have the Pagani Zonda R, because 1) it is so fast, the police doesn't need to chase you and 2) it looks so cool that everyone is jealous. And getting a girl to your home is very easy with a Pagani :P
I would have a Ferrari. I made this promise to my dad that I would get him a Ferrari when I'm rich when I was five. I don't break my promises and I kinda want to get that out of my hair. :P
If we are talking old cars... I would definitely chose the 1957 Corvette (not sure if that pic worked, ) But other than old cars, a Lamborghini is an obvious choice.
Well, any car that costs millions and that I could sell sound attractive. But I might as well keep one: the Phantom Corsair. It has never been sold because it's designer died after finishing the car.