Spoilers ahead! You asked for it — or, at least, one of you did. If you've seen Cabin in the Woods and need to talk about all the plot twists, here is your safe spoiler space.
The thing I have had the MOST trouble not telling people about this movie is that it's the best Lovecraftian story I've seen in ages. But I can't say that because it GIVES EVERYTHING AWAY. But whew, now I've said it.
Also: Giant evil gods. I love a flick where the world is destroyed at the end.