Oh God, you got me started.
Neighbours to the left of me must have a cricket channel, because that's all I can hear from them. That and the usual sports-related noises, ie: cheering, booing etc. They have kids that run around and scream, as little kids do, but at 3am?!? The few times I've bothered to ask them to keep the noise down, someone yells at and smacks the kids, causing them to cry their eyes out for at least half an hour.
Neighbours to the right are relatively decent, although one of them owns one of those sporty motorcycles, and squeals away at all hours of the morning. I think he might have a cat stuck in the engine, with that sound...
The neighbours across from me are the worst though. Parties at least twice a week, that end up with a useless DJ playing "Living On A Prayer", and cutting out the chorus so the drunkards can wail along. I had to help a couple of hungover bastards off my roof a while back. Fireworks from who-knows-where at pretty much anytime of day. Not only that, but they leave garbage everywhere all up the street.