Going to both TEDxAuckland and The Project. Serving different purposes.
TEDx is a great forum for inspirational stories and outside of the box ideas. I went to the 2010 one and loved the eclectic mix - Team One Beep, a writer who walked across Afganistan, the Saami sisters.
Social media events are a bit tougher. I've been to hits and misses - and if you work in the industry a lot of what is said has been said, plenty. I reckon John Lai (from SMNZ) knows this, and he wouldn't plan an event that didn't deliver.
The cost is pretty high but people like myself and other media, and Twitterers, will no doubt be live blogging anything interesting coming out.