If all my previous writing is any indication... I'm a fan of a twist for the audience and protagonist. Something that changes the way you look at the character and previous events. That is the missing key to all the earlier plot-points, and informs the very end and how you should feel. It's always where I start when I'm coming up with a project, and always where I end. I've never written any event-driven stories. Instead, I suppose I've opted for the mystery box, though I've yet to read up on the exact definition.
I'm prone to thinking that the very way storytelling works is through the withholding and divesting of information. Twists are when done right, a very important part of all works. One incorporates them as the dark point near the end for maximum effect. My philosophy is a lot of build up towards that moment. Everything points towards it, from the get-go.
Ideally, I'd want somebody to tell me I'm a 9 or 10, but I'm still waiting for an in-depth review