This is very old, but it's from when I was solo player and wow was just out of beta... lots of years ago.

1 ) As a lowbie undead mage I found the Scarlet Monastery guards. The skull level looked like a target to kill, so I just attacked.

2 ) With my warlock in Deadmines got kicked fromtwo groups because I was "ninjaing" all the soul shards.

3 ) When the soul link bug was around I enslaved all the demons in the balsted lands and became "immortal". Proceeded to wipe an entire horde raid that was doing Kazzak and then finished him. Too bad the hordes got the loot instead of me

4 ) I kited Hogger to the Undercity just to have a guard kill him

5 ) When I finished the internal quest on my warlock I just ran to the crossroads and droppen an infernal just to have it turn on me 15 seconds later.

6 ) Summoned doomguard and infernal in goldshire and let them on rampage just to see a horde raid going to SW oneshot them