Who does more to promote atheism?

I'd say the "arguments" of the theists as well as their respective holy books. They're almost shooting themselves in the foot and ensuring that no one with critical thinking skills is even capable of believing the crap they spew.

Probably Christians who don't live their faith or who preach off-the-wall concepts, or people who claim to be Christian but don't know what it really means. These are the people that turn others off to mainstream Christianity in general. It gives us all a bad name.

Fundamentalist Christians for sure. Keep it up guys!

Christians really waste a lot of time pissing people off about beliefs when they could collect money for Cancer research or something

Religious intolerance in general is the best way to generate distaste for organized religion.

Since so many atheists are in the closet, I would have to go with answer number two.

Well, who does more to discredit atheism?

Christians who live their religion and teach others about coming to Christ and receiving blessings

or

The kind of hypocritical atheists that spend their time on Yahoo! Answers ridiculing people's beliefs without taking a moment to try and understand them

Sorry for your flawed outlook, friend. There are bad apples in every bunch, and a bigoted atheist can do as much (or more) to strengthen a good Christian's faith than than a hypocritical "Christian" can do to put people off.

I thank you and all those like you for strengthening my understanding and belief in the workings of God. ;)

It is a two-pronged approach.

I put the fundies up to it, because they help the atheist cause.

Fundamentalist anything, rather

The nutters with the cults, for sure.