Most boards slow enough tend to have good discussion. The more people there is in a board, the worse it is. But if you want actual discussion you'd be better off in a forum though. Accounts being mandatory to post and the registration process weeds out the garbage people (OP) and their garbage discussion.
Only retards fall for the "4chan is anonymous and has free speech and therefore is better" meme. If you want any kind of meaningful discussion you have to discriminate through identity of the poster, otherwise you're looking for diamonds in a dumpster.
That is the red pill on 4chan and all the other existing forms of anonymous forums.