Oh can I relate to noisy neighbors!
My friend and I moved into the bottom floor of a three story apartment complex. It was rather nice at first - the patio was right infront of our cars, we weren't facing the West so the sun didn't bother us in the mornings...etc.
Well our neighbors above us weren't married but had children. Unfrotunately I was in the room below the children's bedroom. All I cal say is that it gets rather annoying when you are awakened by some child jumping on the bed at 6 a.m. or at 8 a.m. on the weekends! Not to mention, they kid(s) would run around and then jump. Kinda like she was running and then jumping once she stopped. That gets rather annoying when you're trying to watch tv. But the above instances didn't cause for me to come unwired.
One other time I came home for lunch from school and all I could hear was some heavy metal music BLARING in the living room and the sound of two people going at it. Worse yet I could SEE my living room ceiling bounce

So I simply went into my room and blared a teeny-bopper type cd and I think they got the hint
Overall I think the most annoying thing I encountered about apartment living is parking.
Like I mentioned above we had parking right outside our patio. So why was it that when my roomie and I would come home late from the gym we would have to park in the other apartment complex's parking? It drove me nuts because some stupid lady and guy who lived in the other complex would park in our lot. I don't know how many times I was tempted to leave them a note but never did

Worse yet, I would get infuriated by those who'd park and take up TWO spots! ARG! I'm so glad I don't have to deal with that anymore!