I remember coming up with Pascal's Wager when I was in my twenties, even though I'd never realized that Pascal thought it up first!
At the time, I couldn't think of an adequate response to it. Fortunately, I learned. Here's my favourite refutations of the Wager:
1. Bertrand Russell response - "But Sir, you didn't give us enough evidence!"
2. The "Which God?" response - Pascal was assuming Yahweh in his argument. But, if god is really, ummmm, Thor, then Pascal's bet fails no matter what you bet on. If you choose to believe in Yahweh, or not, you still lose and go to Thor's hell.
3. The "Worst God!" response - It's better to believe in the god with the worst Hell since the Hell of all other gods will be less severe. Paradoxically, this means believing in a god that is able to dream up the most Evil Hell - not a trait I would want in a 'loving' god.
4. The "Atheist Heaven" response - If I discover, after death, that god exists and it asks why I never believed, I would explain that my logic and reasoning abilities must have come from god and I must have been expected to use them. Using them to the full extent possible showed that god must be improbable. Wouldn't god make heaven available to those who used all the abilities that god gave us and decided god wasn't there? Heaven must be for atheists!
Anyone have any more? Anyone? Anyone?