Ranking by stars or forks is not working. Each promoted or created by a famous company repository is popular at the beginning. Also it is possible to have a number of them which are in trend right now (publications, marketing, events). It doesn't mean that those repositories are useful/popular.
The gitmostwanted.com project (repo at github) analyses GH Archive data in order to highlight the most interesting repositories and exclude others. Just compare the results with mentioned resources.
