I know it is a big claim, but I think that Linus Torvalds will be more famous for creating Git than for this work on Linux
Linux is a great example of OpenSource development and a good OS. Its impact is mainly technical and behind the scenes.
Git is a hashed-based file system with built-it version control. Its impact is not only technical but social.
The more I use Git, the more I appreciate its beauty, simplicity and ability to scale while handling complex workflows.
See A must watch TED talk about GIT and democracy for an example of how Git can/will be used to change how information is managed in our society.
Also think about the power of having a 'Git Powered' OS (where all files and actions are Git controlled/tracked). We could finally get a lot of security, resilience, quality assurance and traceable from the multiple software/APIs/Apps that we use/consume.
Git also allows its technical users (like me) to be creative in finding ways to improve their productivity and workflows. See Changing a User’s ExpiryDate from GitHub hosted file or these Git, GitHub and NGit posts, for examples of the wide range of areas that I have been using git for (in TeamMentor and O2Platform development)