Warning: it is utterly impossible to speak of Drew Goddard's and Joss Whedon's The Cabin in the Woods without spoiling it at least a little, even if one is only coming to gush for a few hundred words in the vaguest of terms one can get away with, so if you want a completely undiluted experience, just go and watch it - it's definitely worth it.
And now to the gushing: imagine, if the Scream films had been made by someone who wasn't satisfied to stop at pointing out its genre's failures and then just repeat them without any actual change except for the pointing and laughing. Imagine a film that not only points out these failures, but actually uses them as the logical base of its plot, criticizing and deconstructing the mechanisms of large parts of the horror genre as seen on film, and giving voice to the unease the ritualization of a sometimes frightfully conservative genre can produce in a fan whose ethical convictions are anything but close to that conservatism. Now imagine the same film still being utterly in love with the horror genre, paying homage to other films in it with conviction and style, and being able to fuse this love and its critical spirit into a movie that also always works as a horror film (which also means that you can read the movie as one of the more depressing films you'll see this year).
You got that? Well, you might have just had a nerd religious experience, or you now have a mental picture of The Cabin in the Woods, only without the fact that the film is also funny as hell, subtle when you're not looking, has an obvious political subtext, and never looks down on its audience or its chosen genre even though it sees some of what's wrong with it.