I would recommend an Audi R8, if you are going for speed, as it has good handling, and is very fast in a straight line. It also doesn't stand out anywhere near as much as it's mad Italian rivals.
If you are going for something that is more of a city patroller, I would go for an Impreza, or Evo. Both can keep up with criminals down the short city straights, and are super fast through corners.
If however you are like me, and wish to avoid the good handling of a 4WD, I would drive some form of muscle car, swaying towards the Mustang, just because I prefer it over the Camaro.
I like being different though, so I tend to use my Chrysler 300C for faster circuits, and my Audi Quattro for city circuits.
It's all personal opinion really, and what you want to use your car for. You wouldn't want a car that was a issile through corners, but lacked speed down straights for Sarthe would you?