The Carrera GT and Enzo are no longer in production - so they really can't be valid selections per "only the ones that are available right now, straight from the factory (so no second hand models)."
Sad, because of the list posted above, the C GT would be my pick.
Given what's left behind I would pick the Zonda F.
If used cars were allowed then I would select something a lot more special to me. No prizes for guessing .