This movie is opening this week, and is a great film for atheists.
I don't want to give away the story, but the main character, played by Nicole Kidman (who is also a producer for this movie), rejects using religion to cope with the death of her three year old son. I saw a pre-released version, and I think it is well worth watching.
Support Nicole Kidman's project, and maybe we'll see more films with an atheist angle!
Also, Netflix offers it on disc. It's pretty Hollywoodized, but if you leave out the "slave who loved her" subplot and the speculative overstatement of her discoveries, it seems essentially correct.