I'm at first surprised to have a Challenger in that mix but the more I look at the Challenger and then compare it to the other cars, then take a step back, it does seem to fit in. As far as old muscle cars go, the Challenger has unique all around looks, as did many Mopars of that era. There were too many cars that tried too hard to imitate another car and the Challenger was a clean slate design.
I do agree though there were somw cars that were left of the list. There were many 60's Ferrari/GT cars that were beautiful, one I feel is unique and makes use of a clear hood scoop and fender scoops was the 1961 Ferrari 250 TR 61 Spyder Fantuzzi or a 1963 Ferrari 250 GTO . Lamborghini Countach was like nothing else and defined the shape of a Supercar for years....