I've had a bit of success with getting people to understand Bayesianism at parties and such, and I'm posting this thought experiment that I came up with to see if it can be improved or if an entirely different thought experiment would be grasped more intuitively in that context:
Say there is a jar that is filled with dice. There are two types of dice in the jar: One is an 8-sided die with the numbers 1 - 8 and the other is a trick die that has a 3 on all faces. The jar has an even distribution between the 8-sided die and the trick die. If a friend of yours grabbed a die from the jar at random and rolled it and told you that the number that landed was a 3, is it more likely that the person grabbed the 8-sided die or the trick die?
I originally came up with this idea to explain falsifiability which is why I didn't go with say the example in the better article on Bayesianism (i.e. any other number besides a 3 rolled refutes the possibility that the trick die was picked) and having a hypothesis that explains too much contradictory data, so eventually I increase the sides that the die has (like a hypothetical 50-sided die), the different types of die in the jar (100-sided, 6-sided, trick die), and different distributions of die in the jar (90% of the die are 200-sided but a 3 is rolled, etc.). Again, I've been discussing this at parties where alcohol is flowing and cognition is impaired yet people understand it, so I figure if it works there then it can be understood intuitively by many people.