It could be old or new but on concept cars.
Mine is the Mclaren F1
It set the record for the fastest road car in the world, 240 mph and this was in 1998. It also won the le mans 24hr. Its half a ton lighter than the new Mclaren MP4-12c Half a ton !! And the best thing about it the drivers seat is in the middle nice.





porsche 959 ... hands down.
road wise it brought so much to the front of what a super car needs.high acceleration,great handling due to its 4 wheel drive and it looks sexy as hell ( opinion biased maybe) but not only on road achievements but off road also ( converted granted ) it had sucess in the paris dakar in 1986. three cars entered and finished 1st/2nd/5th. .. how many lambo's, ferrari's, marcos, aston's have ever attempeted such a thing?
so for my money, porsche 959
a true super car as much as ayrton senna is a true driver!
edit** when i was a lad .... 959's were THE car. F40's for me were to .. pointy .. countach's were to padded on the wings. the poster on my wall was a 959 with a stocking clad lady on the bonet.. not bad for a 12 yr old eh
. hence why the first design i bought on forza 3 was a rothmans 959 dakar livery. and if i were to win the fabled lottery it would be the first super car i would buy now. i have my eye on 2 