If you prefer to own the series permanently rather than rely on a subscription, you can purchase it through various digital storefronts or as a physical box set. Digital Purchase

If you want to own the series digitally for "download" and offline viewing, you can purchase individual seasons or the complete collection on: Apple TV / iTunes : Often sells "Complete Series" bundles. Google Play / YouTube TV

The most reliable way to access every episode is through subscription services. These apps allow you to on mobile devices.

If you have a subscription, you can download episodes for offline viewing without purchasing them permanently: : In the U.S., Hulu is the primary home for