Forgiveness vs. responsibility for one's own actions
So I was just reading this article, "The Virtue of Hate". It argues that the main difference between Christianity and Judaism (aside from the whole Jesus issue, of course) is that Christianity belives that any sinner, no matter how awful, can ultimately be forgiven and redeemed if they accept Jesus, while Judaism believes that people should and must be punished appropriately for their misdeeds.

The article itself is very interesting, but I also find it fascinating that the Right (which tends to be Christian) tends to espouse the latter view, while the Left (which probably has the majority of Jews, and certainly has the majority of non-religious people) is much more strongly on the "forgiveness" side of the fence.