Worst atheistic argument?

[Frank]

Well, it's not very interesting but, in all honesty I think the worst is when an atheist just takes the piss and says that the God concept is so ridiculous and childish that it is definitely the case that God absolutely doesn't exist. Which is a logical fallacy, you can't prove a negative.

The fallacy of The Argument From Personal Incredulity in other words, it's not an entertaining answer, no - but it's honestly the technically worst argument I've heard I think. Because I think any arguments considered worse than this are probably just sub-categories of it.

EvF

You're right to say this argument (a reduction to the absurd argument) cannot conclusively disprove god, but it is a compelling argument all the same (if it's made properly). Plus, reduction to the absurd arguments are great fun. Take this example (pretty common one, but perhaps you haven't ran into it):

Definition of Christianity:

The belief that a cosmic Jewish zombie who was his own father can make you live forever if you symbolically eat his flesh and telepathically tell him you accept him as your master, so he can remove an evil force from your soul that is present in humanity because a rib-woman was convinced by a talking snake to eat from a magical tree...

Oh, the old maxim we can't prove a negative isn't true in all cases.