The local community of Ingress players in my city. It also acts amazingly well as a human-powered search/recommendation engine and mutual help community.
I love Ingress for the discovery factor (there’s many works of public art that simply aren’t indexed anywhere else), unfortunately our local community is a bit toxic so I play solo and use it as an enhanced map more than anything these days. Maybe when 2.0 comes out...
Just out of curiosity, what do you think 2.0 could fix in terms of community toxicity?