The Cabin in the Woods
It wouldn't be a spoiler for me to say that there's no great Shyamalan-like twist at the end of Cabin that'll question everything you've seen prior to its reveal. Nope; it's just a good, old-fashioned film that continues to unravel in the most brilliantly bonkers and entertaining way imaginable just as you think you know exactly what's coming. If anything, the so-called twist occurs before the title card splashes across the screen amid a flurry of blood splatters and co-writers Joss Whedon and Drew Goddard (also director) are very respectful of the audience's intelligence by asking them why they even watch horror films while deconstructing the genre as it follows its rules. It's also awesome.
If I'm honest I'd have to say that the first two acts aren't funny or scary enough but the last 20 minutes had me hawking back to the glorious days of the late-90s when a certain vampire slayer was my idol and Whedon was an absolute God. It's everything that was great about those shows and more because you don't even have to be a fan or have 'Buffy + Angel 4EVA' on your old school diary to appreciate it. Just don't be surprised when The Wayans brothers announce their crappy spoof version in a few months.