People who talk up how good they are or how many times they've done something. I can do sword but I'll never claim I can do it every time or that I'm the best at it. I lay out my skill level in humble terms for others to see. Noobs feel like they have to talk themselves up to be recognized as good. I would rather have a guy that is honest about his skill level, takes responsibility for a wipe and tells us that it is his first run on Crota hard but he's willing to learn and can competently follow a plan.