Now that I think about it, a tradition that teaches an eternal afterlife -- one which is vastly better than this life -- sometimes encourages martyrdom. Islam certainly does. The early Christians seemed to be proud of their martyrs. Is it not said that "the blood of the martyrs is the seed of the Church"? I'm not aware of any atheist analog to martyrdom, unless it's just plain old going off to war for one's country, which is something that most religious people engage in, and atheists too, but that's not really martyrdom. One might argue that atheism places a higher value on life, because of its absence of the impulse for martyrdom. I haven't thought this through, so consider it a rough draft of an idea.
But let me qualify this a bit: I consider all life to be precious, but there are some people I'd rather were somewhere else.