My opinion....
For discussions, the most active that I've found:
In no particular order.
- http://p080.ezboard.com/ftinnitussupport92262frm1  (administered)
- http://health.groups.yahoo.com/group/Tinnitus/   (administered)
- http://groups.google.com/group/alt.support.tinnitus   (Usenet, not
administered)

Ezboard prolly has the most activity.  Ezboard & Yahoo are
administered, Usenet, like this discussion group is not.
On moderated boards like ezboard & yahoo you will find polite discourse
and high ethical behavior because trolls and spammers get banned. On
unadministered Usenet, like this one, you have to learn by experience,
who the people are that setup shop as self proclaimed experts for the
purpose of boosting their egos and/or providing links to their
commercial websites.  Also you get the occasional traditional spam
postings.  On the upside, Usenet, because it is open to all,is the
easiest place to post so you get more newbies posting. To me, newbie
posts contain the most relevent and interesting information.  If you
enjoy reading troll-wars, this is also the place to be.  We've had some
doozies recently.  Take the bad with the good I guess.
You can get RSS feeds of most Usenet groups and the Yahoo group, but
not EZboard.
Try them all.  You'll learn a lot.
For Tinnitus web sites: there are so many.  There are over 400 .com
domains with the word tinnitus in them. 97% of these sites are simply
payperclick or selling an untested product or service, of no value. The
other 3% provide unique and interesting content.
Good luck.
Jim