In some sense, using weighted averages to compare the US to the average value of any set of countries (especially when you don't include Russia, India, or China) is tautological; we're so big, we pull the average toward us by our mass. Still, there is some interesting stuff here.
This visualization shows the number per 100 of students who are at the typical bachelor's degree-earning age who actually received a degree in the year shown. In other words, if the typical age to receive a BA in the tiny country of Karpathia is 23, and there were 100 students aged 23 in 2009, how many of them earned a degree?
The visualization is sorted by 2011, but you can look at any year by hovering just to the right of the year label at the top of any column, and clicking the little icon that appears. Clicking again will sort in reverse order, and clicking again will sort alphabetically.
It also starts off showing the "Total" value, but you can choose just women or just men; I encourage you to do so, as even more interesting details emerge.
Note: Finland has some funky numbers due to a government incentive that caused many students to accelerate a year, so they spike way up in 2008 and way down (for them, at least) in 2009.
So next time you want to say the US is the best, please be sure to make sure you're not talking about degree attainment.