"Gods", a concept too fuzzy to invest belief in .. either way.

[Angrboda]

I'm currently choosing between:
'God Is Not Great: How Religion Poisons Everything' by Christopher Hitchens
'The End of Faith: Religion, Terror, and the Future of Reason' by Sam Harris
'Breaking the Spell: Religion as a Natural Phenomenon' by Daniel C. Dennett
'The God Delusion' by Richard Dawkins.

Which ones do you think is worth reading? Or are all of them worth a read? Also, are there any other books besides those listed above that you would recommend?

I would say all of them. With the possible exception of Dennett, those are all regarded as classics of the new atheism. I read Hitchens and part of Dennett. I had a problem with Dennett in that the pacing was unbearably slow; I think he was wearing kid gloves so as not to offend potential religious readers. I rather doubt that strategy was effective. Perhaps a better book by Dennett is Darwin's Dangerous Idea. I would also suggest reading more widely in Dawkins than just the narrowly focused God Delusion; he is worth reading.

A couple names you may have missed. Most importantly, Victor Stenger, who might be considered the fifth horseman. Depending on taste, Jennifer M. Hecht's "Doubt: A History" is a deep and thorough tour of the history of doubt and skepticism both inside and outside of religion, but be warned that it is longish (~500 pages), and a lot of information, maybe too much; on the other hand, learning about things like the Carvakas, which was a materialist school of Hinduism, is a lot of fun. Not sure who to recommend beyond that; perhaps Michael Shermer, , the skeptics guide to the universe (website and forum), JREF forums, and TEDtalks (videos on the web). I'm told there is a thriving atheist community "on" Youtube, and from some of the videos I've seen shared, a lot of good information and education is available from there. (Oh, and not to assume everybody is familiar with it, TalkOrigins.org is a website devoted to essays on evolution and the creation/evolution debate; imho, it contains some of the best information and writing on both that I've found; you'll learn what creationists don't understand about evolution and science, but you'll also likely learn that you didn't understand it as well as you thought you did, either. Highly recommended.)

Oh! Oh! And I almost forgot. Infidels.org has a deep collection, library, of both modern and historical writing on secularism, atheism, and religion. It's outstanding. (I've heard grumblings about the politics of the management and their forums, but that doesn't detract from the value of the library.)

(ETA: Getting a little further afield, you might consider some of Steven Pinker's work such as The Better Angels Of Our Nature and The Blank Slate. His The Language Instinct is also reputed to be outstanding, though I'm not sure it's relevant to your concerns. Oh, and not as in your face, but still very good are Jon Krakauer's books on Mormonism and the Pat Tillman story, Under The Banner Of Heaven and Where Men Win Glory, respectively; of the two, I'd say Banner is the best and most relevant.)

"The unquestioned authority of the vedas; the belief in a world-creator; the quest for purification through ritual bathings; the arrogant division into castes; the practice of mortification to atone for sin; - these five are the marks of the crass stupidity of witless men."
~ Dharmakirti (Buddhist)