As the title says.
Here is my list:
1. /lol /flex macros when somebody kills you. Especially when they hardly win the fight or out number you. I don't mind those macros if they out play you.
2. People running away from you when its 1v1 until they get help from 2-3 team mates. How hard is it to fight on equal conditions?
3. People popping ALL cds when you are at 10% or less health and there is no other opponents to kill. Just WHY?
I had something else on my mind but totally forgot will add later if remember ;D