"Couldthisbegrav" and... Aggyrwayter (sometimes?), which is a different story.

IronGauge was another. I'm drawing a blank on the rest, though.

GrafitySplurge would be another, but he's used it for only 3 posts.

There was one particular day when he was furiously creating new accounts in order to undermine Sov. He sent me a PM, from one of the numerous accounts he created, that said "Help me! Sov keeps banning me! KILL HIM!" I was laughing continuously for about an hour because of it.