Best Theistic Arguments

[pocaracas]

I am going to debate a theist over the existence of god soon. What are the best arguments you ever heard from theists? Any tips on what topic to avoid in such an discussion? 
Thanks in advance

The best, best?.... Aristotle and Aquinas' metaphysics.
Still, when they come around and say "to this (unmoved mover, uncaused causer, etc) we call god", we can, nowadays, also say that space-time fits the descriptor.
The "god" designation comes with a bunch of baggage in people's minds, while space-time is still something people struggle with.... it's not just space... not just time. Space-time can bring forth matter and energy out of "nothing". Space-time is not in time... space-time is not a box in space and time, it is the framework upon which everything we know of operates.

I've been trying to find some good argument that convinces me that aristotelian forms are independent of reasoning beings, as Aquinas claims... so, until then, I think those forms are contingent on thinking capabilities. Thinking capabilities that we only know to exist in brains, brains that have evolved from simpler survival mechanisms, etc, etc, etc... abiogenesis, planet formation, star stuff, quark and gluon plasma, big bang... space-time? It seems that everything has progressed from simpler configurations to more complex ones, at the expense of everything getting farther away from each other.
We humans are at a unique position today, being able to infer these things... but a mere 100 years ago, it was not so. Let alone way back in the days of Aquinas, or even Aristotle. So they are forgiven to think as they did. And many today should too, for not many dedicate themselves to trying to gather information from many corners of knowledge and make sense of it all.

What I can't understand is the evangelical sola-scriptura attitude. That is just dumb, as evidenced by Ken Ham and company.