HMM what rages me the most...

Spammers (hate spammed chatboxes).

I hate it when players can't play their role in a party (like lets say theres a healer and druid in a party in a game - The Healer does, the druid has healing abilities but instead of taking over the supportive role he keeps hititng stuff. Another Example - The tanker (Warrior) dies and the paladin can take over the aggro but doesnt want to take the damag so he leaves the party die).

I dislike KS'ers and hackers. They ruin a game.

I dislike mmorpgs with an empty playerbase. Like you just see 1 or 2 players running around lol.