macOS High Sierra

I've had my MacBook Air laptop for over five years and it still runs like a champ, mainly due to an operating system that doesn't get viruses or bloated, and the performance of its solid-state disk.  Add to that the yearly, free (I love free) macOS upgrades and I have all the current features without any upgrade pains.  High Sierra is the latest, with the new Apple File System, H.265 video, improved GPU support,Virtual Reality, a new Photos app features and much more.

https://www.apple.com/macos/high-sierra