A free car!

[cybran]

Dodge Viper... hands down...

 

[Neverhoodian]

That's easy:

...hey, the OP never specified that it had to be real.

 

[Dr_Horrible]

I'd say either an old-style Aston Martin (yes, the one James Bond used), or a Shelby Cobra.

EDIT: if we don't care about reality, I'm going with a fully functional Tron Lightcycle.

 

[electric_warrior]

I'd get the most expensive car on earth, i.e. a Bugatti Veyron or something, then sell it. Anyone who would actually want a car like that would be forgetting how much it would cost to run and insure.

 

[yman15]

The Gibbs Aquada. Its a car that turns into a freaking boat!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
What more could you ask for lol

A car that turns into a jet fighter?

I don't think that would be street legal....