Characters who say the same things over and over because the game designers are too lazy or cheap to get them to say more than just 10 phrases.
The worse is NPC's that only have 2-3 phrases and say it throughout the game. Basically Assassin's Creed's "I'LL HAVE YOUR HAND FOR THAT" or Skyrim's "THEN I TOOK AN ARROW TO THE KNEE." Really because you told me that story before 10,000 times.
People who camp. Stop camping. I will grenade you.
Little children on Xbox Live who act their age. You're too young to be playing games like Halo. Run along now before I spank you with my shotgun.
Awesome guns that are too expensive for me to buy in Borderlands but are timed so by the time I do get the money it's no longer available in the shop. fffffuuuuuuu
GTA smurfing with me by making the traffic more annoying when you have to do a car chase mission. I KNOW YOU DO THIS ON PURPOSE, ROCKSTAR.