Anything at an autocross is a hoot. Just show up with any well maintained car and you'll have fun. It really is about the driver, not the car.
I think every driving enthusiast should at least try it. My wife even had a great time, though she probably won't autocross ever again. Especially younger drivers to learn capabilities and respect for the car, and find an outlet for agressive driving (speaking from experience here, he, he, he).