Is America Still the Greatest Nation on Earth?

I have heard since I was a very young child that despite our warts and weaknesses, America is still the best country on Earth. Usually I hear this in reference to somebody having heard a complaint about our political system, or our court system, or another system that has had a recent failure or shortcoming. I would like to ask the question, are we still the greatest nation on Earth, and if so, in what? What does it mean to be the greatest nation on Earth?

So, I set out to look up some global statistics to see if, and if so where, America is still the greatest nation on the big blue ball. 

In many of the statistical areas, America was first just a few years ago, however it seems we are in a slow slide and even highly motivated to continue the downward trend. Figures for skills in math, reading and science in 2009 show the US in 33rd in reading, 27th in math, and 22nd in science on standardized testing. Countries that are highest is math, science and engineering are known to be the most innovative, a label we are quickly losing as colleges are closing down programs in these areas due to a lack of interest while they pack in philosophy and communications programs (which almost guarantee a job at McDonald's right out of college).

Here are a few more global rankings:

Freedom of the Press - Tied for 9th
Global Peace Index - 96th (just behind Yemen and just ahead of Iran)
Likelihood of a Terrorist Attack - 4th
Soundness of Banks - 108th
Beer Consumption - 2nd
Competitiveness - 1st
Tax Burden - 21st
Quality of Infrastructure - 23rd
Deaths in Youth (10-24 years of age) - 1st
Life Expectancy - 24th
Obesity - 18th
Preventable Deaths (amenable to health care) - 14th
Murder Rates (lower numbers are better) - 78th
Prison Population - 1st (738 per 100,000)
Gun Ownership - 1st (39%)
GDP - 1st (expected to be 3rd by 2020)
Privacy Index - Tied for 13th with Thailand

When we consider there are approximately 196 countries in the world (the experts can't agree on this number), we are doing OK in some areas, however considering the above rankings we certainly are not #1 in many areas. Over the last few years global position in economic factors has taken a large dip. Prior to 2008-9 most of the countries of the world pinned their currency to the US dollar, however this is no longer true as the US dollar is no longer considered by many to be safe. There are many other areas we could cite as well.

So what does it mean to be the "best nation on Earth?" Do these world rank numbers indicate we are not the best, or are we still the best, only in areas that are more difficult to define? Is it possible we are sliding and continue to slide while we pat ourselves on the back and tell ourselves we are the best, further blinding ourselves to the need to work harder to be the best?

Is it true or has it become an excuse to do nothing as we slide into mediocrity?

(rankings taken from http://www.photius.com/rankings/)