"Christianity and Islam are no worse than any other religion. It's religion itself that is the scam. Of course Communism is up there too, but at best it's a distant second."
This is a popular view. There was an interesting comment on it on, of all places, South Park. Since Matt and Trey make fun of religious figures, many people have assumed they were atheists, and were surprised when they denied this in interviews. One of them said that he (like me) has a kind of belief, but it would be very involved to explain.
So they did a show (a really good science-fiction two-parter) which contained a reaction to that famous book The God Scam. (No wait, that's not the title. It's The God Delusion. But looking for it, I found this amazing site.) Like they said in the commentary to the show, these are such big and complex subjects, that they focused in the show on one of the central tenets of the book: that without religion, there would be significantly less war in the world. They believe that this is a falsehood, man is war-like for some reason, and he will always find something to fight about. In the show, they have a future atheist world where the various atheist factions wage wars about which of their beliefs is the more logical.
As for me: all religions sound silly to outsiders, sure. But how about the dominant "scientific" theory, that everything arrived from nothing in a big explosion? Without explaining what was before or how it came about? That's as silly as anything.