The 3+1 Musketeers Of Atheism

Atheism is rising fast as a coherent, self-reliant thinking and moral framework. You may not have noticed because, in western societies, religion is a topic of casual tradition that is of little consequence to everyday life. Of course, this is slightly generalizing - the difference between european and american societies is not subtle. In any case, atheism is no longer an abstract unbelief held by a few eccentrics, but a promising ideology for the future, with a rapidly rising number of followers. Some very remarkable individuals have taken the lead in this paradigm shift, all with their own unique style.
There is Richard Dawkins, who is a renowned zoologist and professor at Oxford University. He has authored numerous books about biology, zoology and evolution. His contribution to the public understanding of the theory of evolution is immense and his own understanding is that evolution strikes a death blow to foundational religious beliefs about the specialness of humankind. His latest book "The God Delusion" is the first that deals specifically with religion and has sold about 1 million hardcover copies already. Dawkins deals with religion in a most scientific fashion, demanding proof for every claim and demolishing popular but false philosophical arguments for the existence of God. His style is calm, clear and only mildly sarcastic.
Sam Harris was an unknown philosophy graduate (who is currently completing a doctorate in neuroscience) before he published "The End Of Faith" and most recently "Letter to a Christian Nation". In those books, he highlights the dangerous irrationalities of religious belief and makes a case for separating spirituality from religion, as a genuine human need that can be addressed without invoking the supernatural. Personally, I haven't yet read a writer that delivers or demolishes arguments with such direct and devastating clarity. As is evident in the many debates he has taken part in, Sam Harris's style is very polite, calm and controlled as the effectiveness of his arguments doesn't require him to raise his voice.
Daniel Dennett is an accomplished philosopher who has made a lot of research in the matter of consciousness and his insights will probably be monumental in the future development of cognitive sciences. While not a vocal atheist, his book "Breaking The Spell" explains religion away in a thorough fashion that highlights the necessity of atheism. His style is somewhat more difficult as he addresses the philosophy-curious person as well as the general reader. Nonetheless, his contribution is important as it deals with territory that is unexplored and severs what few ties religion holds with reality.
Christopher Hitchens is probably the most fearsome of the four. A renowned author and columnist, he is an odd defender for atheism considering he politically leans to the right. In his latest book with the provocative title "How Religion Poisons Everything", Hitchens uncovers religious atrocities across history and the immoralities that underlie religious beliefs in a direct and brutal fashion. In his debates, Hitchens avoids niceties and unearned respect for his opponents. His controversial attitude though is also important because ridicule is a potent weapon that religion hasn't yet faced.
There are other notable writers like Victor Stenger ("God, The Failed Hypothesis") and Michel Onfray ("The Atheist Manifesto") but the 4 above are the most prominent. I am not sure whether these people are leading the wave of rising atheism or simply riding it, but it is clear that things are changing in areas that remained static for a very long time indeed.