I have been involved in a number of partner organizations, but I will rate ASCII very highly on my list.
My vendor friends may get grumpy at me saying this but... ASCII does an AWESOME job of putting their members above the people paying for the booths at their tradeshows. The members have open and frank discussions on the good and bad of the industry without fear of vendor retribution!
Got plenty of others, such as Cost savings on insurance, Social media Programs, Great Tradeshows, but I still like the Member only newsgroup!
Want more comments, I'm not that hard to find. Feel free to poke at me!