If members are contributing their advice, it's because they want to be seen as smart.
If members are arguing, they probably feel insecure.
If members are demanding, they probably want to feel important.
If members are making jokes, they want to be seen as funny.
You should be recognising these, not just with public acknowledgement but with real action.
If a member gives a lot of advice, offer them a top-tips feature to manage. Give the jokers an opportunity to poke fun at the community. Offer those who argue a chance to control the debate of the month section – where each can give their own view and rally others to their side. If a member seems power-hungry, give them responsibility (control of their own group/forum).
When you give members what they want not only does their activity rate increase dramatically, but so does those around them. When they feel respected they're also far more likely to invite dozens of others to join the community. Finally, it show other members that they can get what they really want from the community, if they contribute.