This is probably the most civilized, organized, and friendliest FFXI forum in existence. Here is my opinion... (YES I SAID OPINION) of the other forums most of us use.
KillingIfrit: http://ffxi.killvoid.com/
We all know wtf is wrong with this forum, so many flame wars you don't know which way to look without almost catching on fire. The job forums are full of so much epeen asshats it would differ almost anyone from playing a single job or make them feel inadequate at their job. Trolls lurk this forum like no tomorrow and posting will almost always result in flame wars.
Allakhazam: http://ffxi.allakhazam.com/
Alla is the lesser of the four evils, pikko is awesome plain and simple. This is also the generally best resource of crafting guides or fishing advice. The forums lack customization and want you to subscribe to some nonsense payment plan to even have a signature or avatar. {no *** thanks}... pay for FFXI im not paying for some off the wall forum too. Generally there is a decent .dat mining thread here upon new updates but alot of info is stolen from BG and vice versa.
The Order of The Blue Gartr: http://www.bluegartrls.com/forum/
FIRST OFF... i would love to say that i respect the LS as a whole. But the forum is a complete and utter waste of time with a user base and ego the size of a plane full of dog ***flying to Miramar. The advanced thread is such an epic "who has the bigger *** or opinion" contest that it's amazing people even post there so much. While this is all true i do still browse for a good read every now and again for useful info, but after reply 1 or 2 you start to notice a trend in the replys. Posting there for the average player is asking to be belittled and it's sad to see such oldfags try to act cool in a place they think they feel it's safe to do so. /endrant.
Dreams in Vanadiel: http://www.ffxionline.com/
Lower populated and less used. Late to the race and all information users post or found there is from another website or source. I've noticed a little community of friends but that's about all it amounts to in the end.
In my short time posting on FFXIAH forums, i have noticed a great sense of community and actual help with little flaming or arguments involved. Sure they still happen and we have occasional player warning thread wars but, hey this place is pretty friggin nice. Not only can you do your market research here, but if you wanted to share your actual thoughts or get new ideas the people here are generally more then willing to help in a polite manner.
I know not everyone will agree with my opinions of the forums above but from what i can tell this is by far the most civil and friendly place to talk about the GAME. Because it is a game after all.
So from the few people i've joked with and talked with so far, i appreciate the way everyone here acts and replys. It's about as clean and useful as an internet forum will ever get. Let's hope it stays that way.
To the developers and mods of FFXIAH, thanks... seriously. Keep up the great work.