Hi everyone... ^_^
I've been procrastinating a lot lately and visit Yahoo Answers a lot, as well as pop into GoG occasionally too. After reading some of the most vile questions and answers on YA, I was motivated to start up a thread here asking everyone...

What are your best and worst community sites you have ever visited and/or still continue to visit? I'll start:

BEST
- GoG.com (I'm not trying to be a suck-up, but I found the community at GoG to contain mainly flexibly mature-minded people, even with the ones I've argued before which btw, I apologize to if I went out of line a bit then)
- Thottbot.com (before they were eaten by Wowhead.com)
- Thottbot-Legends.com (very quiet these days, but had a good history)

WORST
- Yahoo Answers (it's a mix of course, but I find that the site is so full of crap, it's sickening)
- YouTube (again, it's a mix, but still a lot of crap and trash and my god, the endless debates in religion and politics is astoundingly tiring)
- PlentyOfFish (was a member there a long time ago, but the forums were often full of haters, trolls and flamers)

GOG, TES forums (haven't been there in years, though), a certain russian piracy forum - near the top.

Neowin, Ars Technica, The Verge - near the bottom, as every post is X vs. Y vs. Z.

ArsTechnica (but only certain sub-forums), StackOverflow for fast tech answers and Quora for non-tech answers.

There are countless other sites I keep track on through RSS but never actually get involved with community-wise.

Gog has a decent community but not great in my opinion. There are great things about it, but the members who do those great things (give away games, engage in good discussions sometimes) are also very inflexible, unreasonable, and childishly rude about other things.

Punknews.org used to have a great community. This is probably the one site that qualifies as an answer for me.

The absolute worst, most scum filled forum I've ever seen was the old yahoo NEWS message boards that you could access only at the bottom of their news articles. I have never seen any other forum come close to the vile opinions that dominated those message boards. This was a long time ago before trolling became a common word and activity to do. These people were mostly serious.

Most terrible message boards today are troll havens. The yahoo news message boards was a haven for genuine racist, sexist, etc who liked to share their opinions in the meanest way possible.

Well I don't really frequent forums very much so for me GOG is currently my favourite forum (although the forum software is pretty bad), my second favourite one is the one for a group of friends with whom I play Minecraft occasionally.
A long time ago I was a moderator on a Dutch forum and that was a pretty fun forum, but after a while it deteriorated because of all the immature new members (which tends to happen to forums a lot). The worst one was an American racist forum a stumbled upon during one my Googles.
At first I thought it was some guy being hilariously fake racist.. but it turned out to be a real racist forum.

GOG's community is quite good, and by gaming forum standards, it is great. I also find the communities over at Just Adventure & RPGwatch to be quite nice, as are The Waaagh (40k-related) and the official Battletech forum.

Worst one I've ever tried to join was the xkcd forum. People were just rude to each other, for no reason other than to be rude. It seem to have become a part of the forum culture.

Forums built around major news sites tends to be pretty bad as well. It usually just becomes a shouting ground for people with inflexible political views, who tends to think that their political belief invalidates all others.

Gog has the best community of any forum i've ever been on, but the competition isn't exactly stiff... What exactly are they inflexible about?

Mainly GoG and Cemetery Dance.

If I'm looking for an answer to a particular question, I'll look on a specific forum, but I generally don't tend to "hang out" in any of them, except here. I think the members here are generally more well-spoken and thoughtful than on many other outlets.

But as far as "inflexible, unreasonable, and childishly rude", I don't think so. Some people have strong opinions and won't change them no matter what, and they'll defend them, but if someone is over-the-line rude about something, he/she will be called on it.

GOG.com, hydrogenaudio, TNAInsider, Arsenal-Mania are pretty good although they're not great at all time.

I post on GOG mainly, with brief excursions to the Steam and Giantbomb forums. I joined Eurogamer not long ago to talk about my new console, but haven't really dove in yet.

For news I go to eurogamer, bluesnews and sometimes check the blogs when I'm bored.

I love giantbomb quicklooks for evaluating games, but I differ from their personalities too much to trust their reviews.

You can still find idiocy of this quality on the comments sections of the Yahoo news articles. It's like they make it a point to be that way, so I can only assume if there are still forums with these people, they must not have improved much over the years.

Few which stand out:

Shacknews, I used to really like the community there. I lurked for years and then posted for years after, but I haven't visited it in a long time. I didn't like the way things were going after they were taken over by gamefly, but of course things could have changed again by now.

Battle.net, horrible community, but I think it's just indicative of the vocal range of the dicklords which show up when a community reaches that size. After the release of a new game/patch/expansion/whatever the forums are pretty much unusable.

Oh and on the offchance a daily mail site gets linked the comments there are legendary. Mostly it's people trolling but the thought that 1/10 may be legit is what makes me triple check my door is locked at night.

I'm only ( active ) on the GOG and Telltale forums . Don't care about the Steam forums anymore ( received a temporarily ban some minutes ago )

Stay away from General Discussion or similar subforums and you should be okay. Most players that actually want to talk about something, write their posts in class / race / story / trading / whatever specific subforums. The ones for general threads are full with whiners. :)