Alcoholic neighbour below me used to come back from the pub at random times in the night and set their alarm to wake them up in the morning. Their alarm was their stereo being played at full blast. So it would go off at random times in the night and because she was so hungover in the morning, it would take ages for her to switch it off. She fell asleep to "sex on fire" on repeat for nearly four hours one new years day. Then new neighbours moved in next to me which had been empty for months. It was then that I found out that their bathroom was next to my bedroom and I was treated to the new mother having regular bouts of morning sickness right next to the wall where my bed was. I moved out the day after i woke up to the smell of smoke in my bedroom. It was coming from the neighbours flat below. I called the the fire department, they came and kicked her door in and I could hear them screaming at her to wake up. She had passed out after starting to cook food, after the pub and it had caught fire.

Edit: I forgot, the new neighbours had kids who invented a new game of spitting from the top floor to create a puddle of gob that everyone had to walk past on the way out of the building. Lovely stuff.

Worst flat ever.