So the most effective personal argument I have ever heard, believe it or not came from my son.  No not work, that usually ends with if the Captain wants it, the Captain gets it.  However my son, I think is spawned from Johnny Cochran himself.  He has the gift of spin.  Now he is seven going on 20, so everyday he is finding more of himself and his independence, but one argument does stand out against all the rest.  
This occurred earlier this school year.  My son was addicted and I mean addicted to this Star Wars game on the Playstation.  He loved to play it with his friends, with me, and role playing in public as a Wookie.  Well one day he got a note home from his teacher because he decided he was going to be a Wookie and do the Wookie talk all day in class.  Now, as a parent you laugh a little inside because you are like, yes the Wookie in the class is mine, then you laugh a little because you think of the poor teacher who deals with something like this all year, and finally you laugh because you need to get your game face on and provide the punishment.  So we took the Star Wars game away for two weeks.  The first night was difficult as he tried to call our bluff; the second day was a repeat but not as bad or long.  Then however quiet.  Day three nothing, day four nothing, he was a perfect angel and even got great notes home from school, and now you could see something plotting in his eyes.  Day five came and again nothing, just another good note home from school.  That is when he approached us.  My god you would have thought he took this class.  Being grounded for only 5 days out of 14, my son gave us a proposal to let him have his playing time back.  He showed us how he has learned his lesson, telling us he now knows that he can’t role play Star Wars in public and not at school.  Armed with three good notes home and a sticker from music and art teachers, he provided examples about how his behavior has changed.  Going for the Oscar award at this point, he even played it up on how much he loves us, how great we are as parents and how he will only use the game now to play on the weekends when he is bored.  There it was everything in this chapter: long term analysis-only playing on the weekends when he is bored, need for presence-he played to our hearts throwing that “I love you mommy and you are great parent”, he gave evidence of a changed behavior-I swear he bribed his teachers or something, because that week every teacher gave him a note home that was based on him being so helpful and good. 
            Maybe it was so compelling because it was from a seven year old, but it left us speechless.  Our defenses fell so fast, it soon became a race to say “ask your…..”.  My wife of course won, leaving me as the only barrier between him and Wookie gold.  I’m sure you know how that ended.  Since then he kept his word, plus it helps that he moved on to Plants vs. Zombies.