I've attended 3 of NASAGA's conferences, and they have consistently been the best conferences I've ever attended. What I appreciate about NASAGA is that it is a community of practitioners who are oh so willing to share AND have fun in the process.
For anyone who is interested in integrating meaningful fun activities into their practice, it is a must attend conference. There are certification pre-conferences in game design and facilitation that are run by Thiagi and his minions.