Fact Checking websites
Here under some links to fact checking sites of reasonable quality (the first two seem to be great investigative journalism sites with an opposite bias).
More to come later (you may add some!). Here a couple more, related to Global warming:
In time we should do some ranking.
It should be noted that Wikipedia also has a list of fact checking sites:
Free discussion here: Special:WikiForum/Fact_Checking_websites