Whenever I'm asked a loaded question like that, I've taken to restating their question without the phrase "the truth." I just can't stomach it to support someone calling it the truth these days. I honestly think that's the worst part about being around JWs these days - the constant "the truth" this and "the truth" that. It's gotten to the point that I have to excuse myself to stay sane.
I've also found that honesty in this situation can be a fun way of shutting people up. "How did you find the truth?" "Well my parents raised me as a JW so I didn't have much choice." Usually you get an uncomfortable silence and a quizzical look before they change the subject. Most JWs' faith is so thin that they're too scared to explore a topic if it looks like it's not going to result in getting 100% positive feedback about the cult.
Also, another fun way to approach this type of situation is if you find someone that was recruited and you find out (as is often the case) that it was after some traumatic event in their life try saying something like "Wow, you're really lucky you found the JWs. After something like that, I bet it was hard to think clearly - if things had been a little different you might've ended up a mormon or something!"