Ask HN: What sites do you block from your search results?

[markahern]

The web is filled with content farms that tailor their content purely for SEO and advertising.

What sites do you block from your results and why?

[markahern]

I block: w3schools.com, I think it's fairly well publicised why these guys aren't a good resource.

about.com, I dont like getting my results from content farms, and these guys seem to show up for almost everything.