I'm working on a very complicated novel involving twin brothers, the end of the US, telepathy, and a gun named "Coraline". So far there has been a helicopter, a wedding, and lots of repressed anger.
Like the NaNoWriMo I wrote last year, I started this only after I worked out how it ends (not prettily). But unlike NaNoWriMo, it's been slow and painstaking and the characters end up in situations that I hadn't planned and things happen and the parts that I thought I would linger on barely get mentioned, while blood and gore (well, gore) cover the pages. I've also been getting hung up on every other page with scenes that won't work, and obssessing about them until they do.
It is quite possibly my most favorite--and my most pain-in-the-ass story. Kind of like the Tweeb.