How to easily defeat any argument for God

[Acrobat]

I don't think you are talking about nihilism here, the belief that life is meaningless.  It doesn't follow from the universe itself having no essential absolute meaning because people create their own relative meanings, both from their human nature and by their specific interests.

No, I'm talking about nihilism, existential nihilism to be exact. Theist tend view life as possessing some intrinsic meaning, not the extrinsic sort your describing, the relative meaning you and others might supply to it.

The first cause argument you're referring to, isn't everything requires a creator. That's an atheist straw man of the argument. 

It's everything that is contingent has a cause. Something that exists by necessity, that is uncaused. Or else you'd have an infinite regress.

Yes, I have heard that variation of the theistic argument as well, and as you say it deals with the problems of the more simply stated argument.

However, in that case one of the atheistic answers is that there are certain things which are known to be uncaused, like ratioactive decay and quantum fluctuations.  It is thought that the big bang could have started from a quantum fluctuation, as an alternative theory.

Sure, you can have atheistic version of a first cause, such as you're trying to articulate here. Something uncaused that led to the formation of the universe. But this is what you would be offering as alternative to a theistic first cause arguement, not what caused the uncaused, i.e who caused god?

Further, there are other problems with the argument as you have stated it, like how theists arrive at their very specific God concept.  Why should we assume a First Cause which is said to have created the universe is conscious and willful, as a God is assumed to be, or even good and moral for that matter?

So as I mentioned, atheists have a wide range of arguments to answer various theistic arguments.

That really depends on how you see reality, as an existential nihilist, or as someone who sees it as endowed with anintrinsic purpose of some sort of the other. In the latter reality looks something like a novel, a story, in which we are both it's characters and readers. It's from that nature of this novel, that they attempt to derive the nature of it's author. If we say this reality possess something like an objective good, that we ought to be, one might say this authors cares about Goodness, or is Goodness itself.