Hi Borderreiver,
I had the same problem as you when I was living in Paris. I was the owner-occupier of a small flat, the neighbours (tenants) were very noisy, and I couldn't get their landlords or the police to do anything about it! I've moved to the UK and now I'm going to sell...
I have the same problem where I rent in Bristol. I live in a house which the landlord rents on a room basis. For the first 3 months, it was fine, one of my housemates worked shifts and came back from work after midnight, but you didn't hear her.
Now, for nearly 4 months, I've been living with 2 guys who are on benefits, i.e. they stay in bed till 12noon, and as a result, the noise is noisy till 11pm, midnight, 1am, 2am, 3am, 3:40am...
I get up at 5:40am to go to work so I am very tired, and I'm afraid of losing my job (and I won't get benefits!).
I've complained to the landlord, but he isn't really bothered (he doesn't answer the phone when I ring him up, and only answers every other email, and then only after a fortnight!). Now, on weekdays, it's noisy till 11pm, then the men go to the pub, and they still wake me up when they come back at 1am, 2am etc. At the weekend, it's noisy well after midnight, so it's difficult for me to get up early in order to do the supermarket run, do the laundry, and look for a new houseshare.
Next step is a recorded delivery, but I'm waiting till I've found a new houseshare (will give the notice at the last minute as a landlady let me down 3 months ago): the first time I complained, one of the tenants acted quite menacingly towards me, and also I'd rather have those belongings that I care for in safe storage.
Good luck to you, it's so difficult to find civilised neighbours, especially in cheap locations.