2. The 1964.5 Mustang*
From a historical standpoint, the car is epic, and the one shown is one of two considered to be the very first ever sold (Yeah, two. That's a whole other story). From a performance standpoint, though, the infant ponycar had a long ways to go. As Carroll Shelby said when Lee Iacocca (a.k.a. The Father of the Mustang) told him to make a sportier version, "Lee, you can't make a race horse out of a mule. I don't want to do it."
*Technically, there's no such thing as a 1964.5 Mustang. There's a certain coolness factor in saying "sixty four and a half," because it debuted in mid-1964, but all of the VINs show 1965.