The first group that I joined was the Big Damn Crafters.
They got the name from an episode of Firefly, which is the common thread that binds us in this group. We are all Browncoats...fans of the cancelled show Firefly and the movie Serenity. So we have contests to make the best Firefly-themed items each month and we post promotions in Etsy Promotions that sometimes are themed to Firefly.
If you are fans of this series or just looking for something different, check out the BDCers on Etsy. Just type in TeamBDC on Etsy's search box. There are some very talented crafters/designers on there.