The Lambo Countach comes to my mind first of all. That's a bloody sexy car. 30ish year old. And it still looks futuristic. Ageless, I say.
And then I chanced upon this sometime back. The 1962 Corvette:
http://www.google.com/images?q=1962%20corv...280&bih=858
So.....round. So....shiny. So....sexy.