[ferretchucker]

For the most part I'm a fan of bleak endings. I think they can serve a very important purpose in a lot of films - mostly to remind us that the world is essentially a pretty unforgiving place. In horror they work very well for reminding us of our overall mortality. One of the most powerful examples for me has to be Requiem for a Dream. Absolutely heartbreaking, and a happy ending simply would not have fit in with the subject matter.

That being said, I don't always like them being used. While I'm struggling to think of an example off the top of my head, sometimes they can feel shoehorned in and just a little off-kilter. Occasionally you need that cathartic pay-off and rather than being a shocking reminder that sometimes you lose, a sad ending can just be a flat anti-climax.

Furthermore, I'd argue that there are some seemingly bleak endings which are actually not too sad when you take them in - often hero self sacrifice. Films in which a hero willingly accepts and makes peace with their death aren't particularly bleak because the protagonist accepts the outcome. Alien 3 would be an example of this - the peace with which Ripley welcomes death almost makes this a happy ending if anything.