New ask Hacker News story: Ask HN: Other communities with responses as good as the submissions?

Ask HN: Other communities with responses as good as the submissions?
6 by notpachet | 1 comments on Hacker News.
A friend and I were discussing what it is about HN that maintains such a grip on our attention, and I realized something which is probably obvious to a lot of you: I often spend just as much time reading through and digesting the comments here as I do the original posts. It isn't uncommon for me to learn way more about the subject matter from comments than from the post itself. Are there other communities, online or off, with a similar balance between the quality of the original source material (whatever that means in context) and the responses to it? For example: an online forum dedicated to an esoteric interest; a book club or writing group; your local bicycle repair shop; etc. (A lot of workplaces probably exhibit this balance, but let's leave them out of the definition of "communities" for the purposes of this post.)