Either 666(

), 1337 or 1984 are good enough milestones for me, because of their meanings and not because of their numeric values, but I prefer the 1984, then I'll ask a moderator to change my forum name to "Winston Smith" or "Big Brother" and put a "IngSoc Party Member" or "Thinkpol" special title

With enough time, anyone will reach the 9k mark.
Now the true challenge lies in posting in quality instead of quantity.