My mom's nagging pissed me off so much that I decided to give her all my electronics and I told her not to give it back to me for a whole month. After the month has passed, I would show her my report card. She was happy to agree.
I wanted to make sure my mom would not try to link the good grades she would see on my report card with the absence of video games, so I printed out my last four report cards (my school allows access to them online). After my mom saw the good grades I had for the previous eight months, she admitted she was wrong and apologized.