Look, any borough in London other than perhaps Richmond-upon-Thames has a lot of **** areas. You can't really distinguish the shitiness of Edmonton vs Lewisham, Uxbridge vs Croydon, Barking vs Tottenham Hale etc.
Tonnes of people will say this is fine but say the other is bad while people argue the opposite. How are you to decide for yourself? Accept that it's not going to be perfect but obviously do your research
Most of London is fine. Make sure that there are good transport links in your area and there's a few things to do. For more info consult the London subreddit on Reddit. It's superbly useful compared to TSR.