I have been behind the wheel of all of these car's except the SS, I've owned muscle cars to import's and to tell the truth for the money, I'd rather have a Porsche Caymen R or Corvette ZO6.
If I'm going to spend 50-70K on a car the three you listed would be way down the list.. Hell for 60 grand you could get a fully restored Shelby or Corvette. But if I was forced to pick one.
The Shelby GT500 would be it..that car just looks and feels like it would slap the taste out of your mouth for looking at it wrong.. But please the KR version.
Speaking of insurance I totalled a 1999 Mustang GT 6 months after buying it, it to 1.3 million dollars in medical bills for me and the other people in the car.
I then traded up for a supercharged Buick riveria
I ended up paying almost 300.00 a month in insurance. Hated selling that car.