Theists: What is the most compelling argument you have heard for Atheism?

[Pat Mustard]

What evidence is there of fine tuning? All we have to go in fine tuning's existence is a presupposition made by certain people that the universe exists as it is is because humanity has to exist, an unjustifiable assertion.

This has been all gone over earlier in the thread. You are wrong about how we arrive at the conclusion: 

Yes, and it has also been conclusively proven that a) what you consider evidence for fine tuning is not evidence, and b) even if fine tuning were real there is no current way to lead from fine tuning to god (for example the multiverse hypothesis is a much more plausible way to explain fine tuning than the god hypothesis, at least the multiverse actually agrees with what we know of reality, your god hypothesis flat out contradicts it).

So again, what evidence is there of fine tuning?