This was very amazing.How important is backlink with your Page Ranking?I will give you an example what good backlink can give you.Adobe have a more than 4 million backlinks and 30+ of their page are all PR 10.This are the benefits of backlinks in Search Engine Optimization.
here are some examples of the sites with Page Ranking 10.Go check them out.
Adobe - Government
Adobe - Web publishing products
Adobe - Solutions
Adobe - Print publishing products