Ferris Bueller is a likable guy. He's smart, funny, attractive and seems to have everything going for him.
He personifies the carefree sprit of adolescence, and his actions throughout the movie say, "I've got my whole life in front of me, and I don't have to live by the rules."
And really, he doesn't. Bueller engages in some crazy antics, and there's no real consequence. Cameron, Bueller's best friend, inadvertently destroys his dad's Ferrari, but Bueller himself is never in any real danger, and we know it.
It's not the most realistic film (trust us, everyone involved would face retribution for destroying that Ferrari), but it's fun, quirky and a nearly perfect teenage flick.