The Best Apologetic

In logic and debate, they teach various techniques that are considered to be logical fallacies.  One of these is to attack your opponent rather than attacking your opponent's arguments.  So, for instance, if I am presenting a case against global warming, and my opponent responds to my argument by saying "Yeah, but you never graduated high school, so what do you know?" his response may be convincing at an emotional level, but it does nothing to disprove my premise.
When it comes to presenting a case for the Christian faith, however, this idea of attacking the opponent actually DOES hold some water.  Not on the side of the Christian, but on the side of the non-believer.  The reason I say this is that one of the fundamental tenets of Christianity is that it is supposed to change the believer.  If I profess to believe in Christ and his teachings, but I act no different than I did when I was an unbeliever, my claim looks suspicious at best.
The best apologetic is a life well-lived.  One of the main reason that Jesus is such an intriguing figure to all people-groups the world over is that his life was lived so purely.  Even the most ardent atheist must admit that he was "a great moral teacher." 
On the flip-side, one poor choice can utterly ruin the testimony of the most well-intentioned apologist. 
In the twenty-third psalm, the psalmist says, "He leads me in paths of righteousness for His name's sake."  What the Psalmist is saying here is that God keeps His followers pure because they are representatives of Him.  They reflect his name and reputation, and so He keeps them from straying.  I think this should be the first prayer of any minister, and of believers in general, that God would purify their actions so that they may properly represent Him to the world.
A poorly educated person who is unable to make a verbal defense for his faith, through living out the Christian life in a faultless way, may do more to redeem those around him than the most silver tongued theologian.