I wish searching in Japanese was easier, but this site is an almost godlike source of knowledge about anything. From finding links to torrents to getting instructions on how to change settings on your keitai(cell phone), 2ch kicks ass.
The site is setup well in that clicking a link redirects you to a page displaying the actual offsite link address and letting you know it is going offsite. It puts a level between the site and the linked content which likely reduces liability and adds to overall security of the user.
The text only interface is rather unique for even Web 1.0 forums, but it allows fast loading, quick reading(well, as quick as you can read Japanese), and removes all the annoying clutter like avatars, images, signatures, and emoticons from view.
To say this site is not moderated doesn't cover it. I have seen links to copyrighted content(sometimes the content is posted online), information on making "terrorist weapons", and even child pornography both hidden and posted explicitly without being taken down.
In the interest of full disclosure though, I also visit a lot of other Japanese forums which I prefer over 2ch due to their being organized and on topic.