(I like your other post, and will reply to it. It requires a bit more focus than I have to give right now, but this is an easy one)
Krauss is great... "the Woody Allen of physics".

There's some more stuff on Youtube... a debate with William Lane Craig on the very topic, and another discussion with Dawkins. I had no idea until recently how much good stuff there is on Youtube.
As an atheist, which theistic arguments do you find most compelling?
This is one of those areas where I think a lot of converts are made, on the question of the origin of things. A usual line of reasoning is that the idea of self causation doesn't work, i.e. for material or natural things, they never cause themselves, so their must be a Maker who is SUPERnatural and can therefore escape this limitation on self causation. Now, I know what the words 'super' and 'natural' mean, but I have no idea what something 'supernatural' is (is it a 'something' anyway?). I have a vague idea and can use it in sentences, but it's not a technical term from some area of knowledge or discourse that you can really hang things on.
There are some other ones in this area that I enjoy, like: if there are an infinite series of causes, we wouldn't be here because it would take an infinite amount of time.
The one that hit me hardest was this one I heard from Tim Keller, perhaps via Plantinga and Nagel in his book The Reason for God. I'm pretty certain he mentions it here.
http://www.youtube.com/watch?v=C9fmKSwuoDE. While I don't agree with him, this is a fine and intelligent and intelligible (!) talk.
1. Assume a naturalistic explanation for belief in God: there are evolutionary reasons for religion, direct (religions themselves are advantageous) or indirect (imposing narratives and causal reasoning on nature to explain things is advantageous). It's part of our neurobiology. It's just advantageous and not true.
2. There are also evolutionary reasons for Reason and logic. They are also with us due to their advantage and not their truth.
3. Evolutionary skepticism about belief in God and the validity of Religion also undercut belief in the validity of rationality and belief in evolution itself. "If our cognitive faculties only tell us what we need to survive, not what is true, why trust them about anything at all?"
"It comes down to this: If, as the evolutionary scientists say, what our brains tell us about morality, love, and beauty is not real -if it is merely a set of chemical reactions designed to pass on our genetic code- then so is what their brains tell them about the world. Then why should they trust them?"