Most retarded communities

[NJ5]

In your experience what are the most retarded communities on the Internet?

I probably try to stay clear of the worst ones, but it seems that Youtube comments can make me feel physically sick and reduce my IQ for a while. Sometimes I think "let me check out what people are saying about this cool song", and much of the time there are a bunch of dribbling retards spewing insults and other incredibly stupid comments.