Among street Ferraris, I'm told that the 365GTC/4 has the best note. Among cars that I have owned, the 206SP S/N 002 was the best. The first time I drove it, shifting "by ear", I glanced at the tach and it showed 10,000 RPM. Scared me, but I later learned the 10,000 is OK for that engine. Wish I had a recording to share.