On the Rankings page you can see top 15/50/100 toons with the highest value of a given stat. You can filter results by server, class/subclass/archetype and guild.
You can use this page to see how your toon is doing comparing to other toons in means on both stats and accomplishments.
You can also use it to search for best toons of your class, so you can then compare your toon against them (hover mouse over a toon in a result table and click "Compare to me").

Fun fact - this page was originally created because Kulavvy wanted to see how he's doing on his goal to be #1 of shiny hunters ;)
[Kulavvy]: Yeah, there were times when you could quite easily finish all collections except 2 or 3 like Ydal or Bristlebane.
Not fun fact - queries for All worlds most often cause timeout and give no results.