Destroy The Godmodder: A large number of the characters. One of the more notable examples being TT2000, who happens to be the original creator, whose inherent effectiveness stems entirely from the total lack of effectiveness that his actions inherently possess.
Similarly, there's Tricky the clown. Tricky is the only character to repeatedly defy the curse of repetition, and the only listed reason: He's an insane psycho zombie clown.
Then you have leon and his fish of death. And nimble and his insanity tubas. And pretty much anything that involves jondanger in the tvtropes session.