The "straw that broke the camel's back" for me was the crap in the "Revelation Climax" book about the angels' trumpets foretelling various WT conventions in the 1920's. I could hardly believe they expected people to swallow that tripe.
Then I read Ray Franz's Crisis of Conscience and that confirmed for all time the decision I had already made.
The Truth© is not the truth. Never was. What's worse, the organization has gone from merely being filled with religious error to becoming a prime example of an authoritarian mind-control money-grubbing cult ruling over its sycophants with greedy iron hand while masquerading as God's spokesmen. It could give the most egregious televangelist in history a run for his money.