ehow.com, for example, is considered "bad" by some but each time it's come up in a search for me and I've clicked through, I've found it useful. For example, a few days ago my wife's iPhone 4 broke. I searched for "iphone 4 home screen without button" and eHow's page came first and told me quickly and cleanly how to work around the problem.

I would personally want to block all of those news sites that put interstitial ads in the way when you go to read their articles (e.g. ComputerWorld) but other people who don't mind that would get burned if they 'shared' my list without going through it with a fine toothed comb.

But I'll stick to using my brain as a filter for my search results. It seems to work out quite well.