As you may know Google shutdown the Page Rank (PR) service, so all sites now is PR0 even Google.com, We recommend to go through the Domain Authority (DA) metric by MOZ, What is Domain Authority?
What is Domain Authority?
Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how well a website will rank on search engine result pages (SERPs). A Domain Authority score ranges from one to 100, with higher scores corresponding to a greater ability to rank.
Domain Authority is calculated by evaluating multiple factors, including linking root domains and number of total links, into a single DA score. This score can then be used when comparing websites or tracking the "ranking strength" of a website over time.
You can view a website's DA by using MozBar (a free Chrome-extension), Link Explorer (a backlink analysis tool), the SERP Analysis section of Keyword Explorer, and dozens of other SEO tools across the web.
Features: