Well I stopped "church going" about twenty years ago when my eight year old brother was hit by a drunk driver. He lingered for several days in the hospital before we had to take him off life support. At that time I can say I was a devout Christian. My prayers fell on deaf ears.Soon after I stopped giong to church. Up untill about four months ago I clung to a fear of god and hell that have been embeded in my brain through a life time of indoctrination.
One day I was watching videos on youtube and saw The Atheist Experience. It was Matt and Jeff and they were ripping some christian a new ass. I was shocked and a little bit angry. This is what made me watch it again. I began to realize that the things they were saying made sense and why christianity never did. So the answer to your question in short form is The Atheist Experience or more specifically, Matt and Jeff.