Battlehack is insanely intense - 47 teams judged, a packed house at Level 39, over 48 hours hacking and 5 hours judging.
but the event always pushes the boundaries on crazy activities (a dance-off for swag), awesome devs, and hacks that are creative. the winners integrated Leap motion and the Watson API, not to mention the Sendgrid and Twilio.
it's one of the hackathons i hate judging because it's such a privilege to be in a room of builders and makers. everyone pushed themselves, which is the point of any great hackathon.