I once read that the chance of Russian Roulette is NOT 1:6 but more like 1:600, since you play with one bullet and the weight of the bullet makes it relatively unlikely that the bullet stops next to the top position in the barrel when you spin it. Don't know if this is true but in the end, it doesn't matter for this stupid game.
I love how people have so much trouble understanding the Monty Hall 'paradox', but when you give them basically the exact same problem in the form of Russian roulette then suddenly it becomes trivially intuitive that you REALLY want to spin in between turns.
http://en.wikipedia.org/wiki/Monty_Hall_problem
And I did take probability classes (and passed :) ).