Hello!
Not so long ago, reporting to the customer about the promotion of his site, I decided with pride to write about raising PR from 2 to 4. Well, I wrote that it translates as Google PageRank, that it can be from 0 to 10, and that to increase it from 1 to 2 - not the same as from 4 to 5 and so on, and so on and so forth. Well, I decided, for the sake of comparison, to give examples of what this indicator is in other sites. In addition to sites with PR = [1, 10), it was necessary to give an example of a site with PR = 10 ...
There are quite a few websites, and more precisely, pages, because PR is calculated for a single page, on the Web with PR = 10, and, of course, these sites and pages are widely known, here’s an 
example of a list of domains and pages with PR = 10 to February 2008
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However, the current state of affairs has completely changed.
And this is what happened: I did not check all the sites and pages from the list I provided, but I had enough of checking 
www.w3c.org , 
www.apple.com , 
www.adobe.com , 
www.microsoft.com , 
www.ibm. com , 
www.apache.org , 
www.nasa.gov , 
www.nsf.gov to understand - Google raised the PR bar, but I can’t say, throughout the user scale from 0 to 10 or only at high values. The main pages of all the above sites I tested PR was equal to 9.
In general, in general, recent PR updates were for the most joyful, PR increased. But, as I see, not for resources with PR = 10.
Well, but now they have where to go next!)))
PS: The customer this time never recognized a single resource with PR = 10))
UPD: Currently, sites with PR = 10 total 2: 
www.google.com 
www.usa.gov 
According to materials www.searchenginegenie.com/pagerank-10-sites.htm 
Thanks for commenting, and, in particular, for the link - tigerman