Post Count is a count of any one user's total posts. Many erroneously think that it matters to have a high post count. However, most sensible users agree that the quality of contributions is more important than the volume.
The current highest poster is Rawrzilla. The position was formerly held by Abicion and before him, LedZeppelinfan, banned on January 8, 2006. His permanent post count is at 25,529. Since he had attained the position, many have sought to claim his throne, including Abicion and Sataka. It had become a kind of arms race and many have fallen to the dark side of pure spam to try to reach the goal, Abicion being the worst of them. He surpassed LedZeppelinfan's post count on September 9, 2007. With Abicion's posting habits, it seemed likely he would forever keep this spot unless he was banned. However, thanks to the powers that be, a forum error occurred and a new member was given the highest possible post count upon registering. This has rendered Abicion's post count irrelevant, as he can never hope to match or surpass the new god of the forums, Rawrzilla.
It should be noted that post count is an excellent alt indicator: if any person with less than 300 posts disagrees with anyone, they are an alt.