My mom dances and shakes her but in my direction, knowing full well that it annoys the hell out of me.
My brother (1 year and three months older than myself) keeps hogging the TV, says "Hey little sister?" and then suddenly yells "SHOTGUN" if I don't tell him to stop it, and he keeps screaming and banging stuff out of frustration if he dies in a game, looses the internet connection, or some other trivial thing. Also, whenever he looses the connection or wants to do something on the 360 involving the internet, he swipes the cable I use for my laptop even if I am using it.
Dad, well... The only thing he does that annoys me is when he starts joking again about how he built me in the basement and how my brother hatched from an egg. He also claims that he was born "back in the days when the dinosaurs ruled the Earth" or that he's Satan and that we're the Spawn of Satan. Whenever I tell him to quit joking, he'll ask me "Would I lie to you", to which I automatically say yes.
Then there's the cat. Whenever he sees a bowl, plate, or glass (especially a glass of milk or water or a bowl at all), he starts screaming since he expects us to give him our own food when he's a big tub o' lard that has food in his dish and water in his bowl in the kitchen. Sometimes, he just starts screaming for no apparent reason!