Electrocute. (Does too much damage, doesn't even require skillshots to be activated you'll still proc it with AA's)
Duskblade.( Everyone's complaining about it still no nerfs to it. Wouldn't be surprised if they buff it for Worlds)
Everything deals so much damage.( Early game damage is ridiculous, domination tree gives SO much damage. Still no nerfs to domination tree.)
Tanks not being tanks.( Tanks are squishier then ever before. Instead of buffing their resistences, riot is buffing their damage. Resolve tree doesn't give resistences only gives flat HP.)
People quitting the game because of everything listed above.