The God Delusion is truly liberating, as so many of the posts here say.
I haven't properly believed in God since I was about nine, despite belonging to a church-going (Church of England) family. I can remember doubts starting when I heard a priest give a sermon in which he described hell as not being the eternal fires of Biblical and Sunday School legend, but being merely 'separation from God' . I recall thinking 'oh, that doesn't sound too bad at all! ' and wondering what else in the Bible might be not be 'really' true.
But as I grew up it took a long time to be able to throw off the faint doubts that God, or something like God, might still exist after all – at least not without feeling uncomfortable about it.
Now, Richard Dawkins has made me feel comfortable about it! Atheism is the only respectable intellectual position to have, and as I prefer to think rationally about other areas of my life, why would I not want to do so in matters of religion?
What is scary, though, is the hold that religion has on other people's minds and behaviours. The lecture about suicide terrorists linked to on the home page is well worth listening to, for an accessible account of this.