The Austin Game Conference was great. I met some of the gamedev.net "crew" at the booth and panels, and I made a metric ton of contacts. Not to mention learned a lot that directly applies to what I'm doing.
I think I spent a whole $650 on travel, hotel, and con badge (I drove)- not a huge investment, especially compared to GDC.
I plan on returning next year...
P.S. Austin is an awesome town to party in!