My fav is definately the McLaren F1 GTR. 👍 👍
Ever since I got GT4 I've been running that car and loving it.
Once I get the time to start racing arcade mode again I will try to break under 5'26 on the Ring with the Big Mc.

(right now I've stopped to take a break after managing a 5'26.9)
So my Fav, definately the McLaren.
Here's a picture of the McLaren (which I'm sure plenty of people have seen.
Also, if we are going to include the Zonda (despite it not being the same car), then I also suggest you include the NSX LM. 👍
(and yes, I am well aware that this is not the "exact" car from GT4)
Finally, here's another picture of
A Zonda race car (although it is not the exact one from the game (since afterall, the exact car from the game does not exist).