That poll is the 2011 version. If you click through from the blog to the website you can view the 2012 version, in which Britain is sixth, and in which Turkey has gone up five percentage points to have a more favorable view than Pakistan. The countries in the two polls don't all line up, but Russia fell a few percentage points, so did France, Japan took a nose dive, and the US increased its liking of itself to the top of the chart at 80 percent.

But perhaps a better way of putting it is, "Britain has the sixth most favorable view of the United States (out of these 21 random countries we surveyed)"