I have a few favorites whose posts I usually read with interest. Like BoulderJohn I won't name them for fear of forgetting someone, but I will say he's on my list.
The people I like to read are the ones who have something pertinent to say but who are open to respectful discussion and willing to accept that their own point of view is just that, a point of view....one of many!
I also especially like posters who draw people out in a way that makes them think about their own thinking by asking "why" and "how" questions (sincere ones, not the cynical rhetorical ones). These people are trying to first understand before being understood (Covey's 5th Habit) and I really like reading people who have the maturity to stand back and observe the thinking non-judgementally without becoming wrapped up, sometimes emotionally, in it. It is possible to discuss something, even when points of view differ, without having a need to "win" the discussion. You can see it when people do this. These discussions are useful, informative and full of mutual respect.
People who start to believe that their point of view is the *only* point of view are closing their minds and when this happens it becomes difficult to discuss things with them. The ones who take it to the point of becoming closed minded and angry/cynical I don't like much at all. If they also become rude and/or belligerent if you don't agree with them then there is really no point in discussion. Nobody likes to wrestle with a pig. You can see these people coming a mile away too because their posts usually boil down in essence to saying "I am better than you because...." and threads where they participate heavily usually end up with an edgy, argumentative and disrespectful tone.
I like the real jokers too but not because of their scuba content. All work and no play makes Jack a (proverbial) dull boy and it's nice to have a generous sprinkling comic relief in the discussions too. Diving is fun so why shouldn't discussions about diving be fun too?
R..