Was never really religious - mum was Church of England (non-practising) and dad a Catholic (non-practising). Went to a C of E infant & junior school (not for any religious reason - I was in the catchment area) but again, it was not massively religious - just the occasional assembly taken by an affable vicar. Spent most of my early life vaguely agnostic, though was (weirdly enough) quite superstitious and tended to find more worth in woo & mysticism than it deserved.
Breakthrough to Atheism came when I was thinking about the god of the Bible one day, and saw the fundamental flaw in the logic - that a god who exercises judgement upon people to whom he has given free-will cannot be reconciled to a omniscient God who knows what you are going to do anyway, and already knows if you are damned or not (thereby negating the concept of free will, and thus his judgement, at the outset). Various discussions about this with religious people have failed to change my position on this (not that it changed the position of the religious lot, either; they merely exercised a sort of religious doublethink on the matter and left it at that) and my Atheism has deepened to the extent that I'm pretty much non-superstitious (occasional lapse - dunno why. I guess we just have a side that isn't amenable to reason, and even the most diehard skeptic isn't immune: even RD confesses to personally insulting his bike when the chain breaks at an inopportune moment), and though I still enjoy the occasional woo-ey book (cos a few of them at least do contain some interesting speculations, IMO, though nothing I would waste time defending in an argument) I pretty much take it all with a pinch of salt.
Nowadays, my Atheism is such that I hold the god of the Bible and Koran to be nonexistent; and that any other religion (that I have heard of) offers nothing that is any more probable. The only 'god-concept' I remain at least vaguely agnostic upon is the uninvolved deist 'god' - the engineer who caused the universe to be and left it at that. But my agnosticism on this comes about only through my own ignorance, and certainly not on the basis that I might see any great possibility of such a being existing.