Well... seeing as my family is now for the most part either dead or very distant... not much.
But when I was younger?
#1. Nocturnal computer habits. I would stay up all night playing on the computer and sleep during the day WHENEVER I could get away with it. That tended to annoy various people. It was more a habit I picked up after I turned 16 though.
#2. Piano reluctance. The fights my mother and I had because she wanted me to play the piano and I downright hated it, but she wouldn't let me near the computer if I didn't... so I had to play two hours a day, including one hour first thing in the morning. I tended to just go downstairs and sit on the piano stool until I heard my mother yelling through the floorboards for me to get playing. This happened a LOT.
#3. My tendency to tease my mother CONSTANTLY about her decision to be a poultry farmer. I never let her hear the end of that. I used to call her a "Poultrémen Trainer" and occasionally jeer "Gotta catch 'em all" at her because of it.... That and I used to sabotage her anti-predation fences and whatnot so the foxes could get in and eat the chickens (I do NOT like chickens, but I do like foxes).
#4. My aggressive organisation of neutral property. For instance... the layout of the kitchen. The use of the chairs around the kitchen table. The placement of items in the living room. It had to be as I wanted it... and I would become VERY vindicitive if anyone tried to change that set-up.
#5. The book-piling. My room wasn't filthy like my brothers... but I had a tendency to pile up my books and schoolwork-folders at various positions about my bedroom (categorised by subject and size, generally)... until the whole thing looked like some mini-scale replica of a city... and a rather awkward to navigate one at that. Since my mother generally wasn't allowed into my bedroom on pain of dire retribution though (I had a habit of enacting my fleeting pyromanic tendencies on her paperwork if she annoyed me), that wasn't such a major problem.
#6. Fly. The border collie. I got it into my head for years that Fly was more trouble out of her basket than in it... so I systematically ordered her to go back to her basket whenever I saw her out of it... pretty much. It reached the point where I only had to LOOK at her and she would run back to her basket and cower there. There were several occasions where she actually tried to face off against me, resulting in mutual baring of teeth and growling.... but she always lost in the end.
Technically she was my brother's dog, but he didn't tend to care about her all that much... and neither he nor my mother thought much of the panic-switch I had basically enabled on her.
Can't think of anything else off the top of my head really.