A model citizen should be one that isn't afraid to question authority, give equal civil rights to all Americans, and who considers the repercussions of all of his actions. Not to go into politics and religion forum territory or anything...
But I think I am technically a model citizen. I pay my taxes, drive responsibly*, I am pursuing my education, I am working full time, I pay my bills (usually), I am registered with the Selective Service, I vote always, I have volunteered in the past with various causes, I recycle, I open doors and assist people in need, I'm a registered first aid and CPR responder with the Red Cross, and I'm a registered organ donor. I'm always nice and always willing to help, because I know there are days when I wished I had somebody to brighten my day... so I always try to do that.
* I sometimes go 4mph over the speed limit, and occasionally up to 10 on the interstate, if the conditions are safe and traffic is sparse (and I'm sure there aren't any popos around!), but I've gotten two tickets and taken classes for each and both times police officers taught the classes and said that they speed too and don't blame speeders who are reasonable (5mph or less on regular streets, 10mph or less on interstate), and usually they can't stop anyone going that little over the limit, much less are they usually interested in wasting the time.