I wish I had more than two, because there have been a lot of important people. But for the most polarizing people with lasting contributions, I'd have to go with:
The Arena Master: One of the first great forumers. When he was actually here he made ridiculous amounts of posts and I can only wonder what the number would be if his account was still around. His opinions and actions often had mixed results but they were no doubt influential.
Mooclan: Look at his signature. That's all that needs to be said.
Honorable mentions would go to
HalfSquirrel,
Zeno and darkai202, who all also made a considerable impact. I don't really want to nominate myself because that would be kinda tacky.
