Il Leone - definitely agree on the Mangusta, I saw one in the flesh for the first (& only) time this year and it wasn't until I got over the surprise that I realised there was another Mangusta beside it! With ~400 built you can imagine how many there are in Australia.
Beautiful American cars - some I would nominate as beautiful although not "the" most beautiful are
Buick Riviera
C2 Corvette roadster (especially in a light-coloured metallic paint) The Sting Ray coupe version wasn't bad either!
Studebaker Golden Hawk