I am breaking my Friday-Only writing rule to answer what I think is an excellent question by a Mr Ruiz:
Who do you consider to be the most articulate and firmly-grounded spokesmen for atheism? Who did you read and admire prior to your conversion?
In not quite Chronological Order:
1. Lucretius (albeit technically a type of polytheistic deist)
2.The anonymous author of the TREATISE OF THE THREE IMPOSTORS (admittedly, this one I recommend more for its interest as a historical curio than for the rigor of its logic)
3. Thomas Paine Age of Reason (again, technically a Deist rather than an atheist, but close enough).
4. Colonel Robert G. Ingersoll– Nearly anything by this author is worth reading for the committed and serious atheist.
5 Hume, An Enquiry Concerning Human Understanding – Useful for erecting a naturalistic basis of ethics and epistemology.
6 Locke, An Essay Concerning Human Understanding – Likewise.
For lighter reading, I recommend men who are lightweight thinkers, but less dry and more entertaining:
7 Stephen Jay Gould
8 Carl Sagan
9 Mark Twain
10 Ayn Rand. Despite the unbridled and often unbalanced passion and vehemence of her rhetoric, she is careful enough to identify her axioms explicitly and draw out the steps of her arguments rationally.
11 Nearly anything published by the Committee for the Scientific Investigation of Claims of the Paranormal led by my one-time hero, the Amazing Randi — a group admirably limited in his goals and disciplined in its methods. Not atheist per se, but strongly naturalist and antisupernaturalist.
12 Thomas Hobbes. Anyone wishing to see how philosophy is done rigorously and done well should read his LEVIATHAN. Since the conclusion of the argument, a justification for totalitarianism, is one for which all modern readers ought feel no attraction, the naked and skeletal beauty of the process of logical reasoning is more easily opened to the gaze. Not an atheist per se, but an enlightenment style rationalist so naturalistic in his assumptions and conclusions as to be a must-read for anyone calling himself an infidel.
Authors I would recommend avoiding include Nietzsche, who wrote not a single sentence that logically followed its next, and include Richard Dawkins, master of historical errors, who is to atheism what Paul Erlich is to Demographics, an embarrassment to the cause.
Atheist authors Christopher Hitchens and Sam Harris I have not read, and so voice no opinion on the quality of their work.
As one can see from the shortness of this list, as an intellectual movement, it has neither deep roots nor any truly rigorous philosophical defense. There is no one of the stature of a Thomas Aquinas in its ranks, much less a Pascal or a Descartes or a Newton, or even a Saint Anselm. The idea that the universe, including man, is natural and has no supernatural component is difficult to articulate and difficult to defend, and runs counter to the common experience of mankind, as well as to instinctive sentiment and intuitive knowledge.
Hence, what is more useful to the would be atheist might be to read the Summa Theologica of Acquinas or the CITY OF GOD by Augustine or the popular apologetic writings of C.S. Lewis, and come up with arguments against these strongest of Christian arguments. Study the enemy. Do not walk up a blind canyon without flanking support.