Maybe I missed it, in another thread or something, but what is it about JW's that you don't buy? Blood? 1914? If you can nail down exactly what it is and support your position from the scriptures, maybe you can casually bring those things up with your parents over the course of a month or something.
"Pop, why is taking a blood transfusion considered the same as eating blood, but taking a liver transplant isn't considered the same thing as eating liver?" (The watchtower has itself called blood an "organ" and quoted a doctor as saying that a transfusion is a "transplant".)
Maybe you've already prepared yourself for this, but it might be better to show why you don't accept their beliefs rather than outright telling them you don't believe in God. "There's no God" is an utterly unprovable statement, so you'll be in a tough spot to take a stand. But there's ample evidence that the blood doctrine is baloney (I can send you what Gina and I have put together) and that's a false doctrine that can cost you your life somewhere down the road. "Pop, I'm not sure God would want me to risk my life over the blood doctrine, since I'm not convinced that we have that doctrine right." Then it becomes a "But Son, Jehovah expects us to obey the organization" discussion. We just had a thread on that, showing that God punished his own people when they obeyed the "organization" (Aaron) when it told them to worship a golden calf. (See http://www.jehovahs-witness.com/12/83217/1.ashx) So obedience to God is more important to him than obedience to his organization.
Some people say arguing from the Bible when you don't believe in the Bible is a waste of time. And for some topics (Trinity comes to mind) I would agree. But I think you can force JW's into a corner on a few doctrines. Their only escape is to say, "But we have to obey God's organization", and you can make a decent argument against that, too.
Gina found that with her mom, presenting her reasoning on various doctrines helped her mom to understand that she wasn't getting out of JW's just because she wanted to sleep in on Saturdays, or get into drugs or whatever. It might allay your parents fears a bit if they could see that you're making a decision based on not agreeing with their doctrines rather than based on what they'll consider laziness.
Hope it helps. Take care, Dude.
Dave
