This question is difficult to parse. What do you mean "a good example?" You mean a historical society? It's important to realize that there is significant debate amongst anarchists about what an anarchic society "should" be. There are many "flavors" of anarchism, all of which oppose, to one degree or another, the existence of a state, but many of which oppose or condone, to various degrees, what they see as other types of coercive entities.

I believe it violates the rules of this subreddit to ask "throughout history" type questions, so if you're asking: "Has there ever been a good example of an anarchic society throughout history?" in other words, you would probably do better to ask that in either in either /r/Anarchism or /r/Anarcho_Capitalism, which, broadly, aggregate followers of the two primary sides, so to speak, of the debate on political anarchism.

Free Territory is often brought up.

TL;DR version: an area of Ukraine declared itself a stateless zone during the Russian Revolution. Stood independent for three years, then occupied by the Bolshevik's out of fear of Makhno, the military leader that lead the territory's defence.

Note also their cool flag.

But of course, Anarchism isn't one unified ideology. Anarcho-Capitalists for one would not like the Free Territory as it abolished private ownership. Some AnCaps claim Medieval Iceland is close to their ideal society. Anarcho-primitivists and eco-Anarchists idolize hunter-gatherers and indigenous tribes.

Pre-Columbian Native America.